Department of Mathematics, Fall_1999
https://sites.math.duke.edu/mcal?listgroup-0
Department of Mathematics Upcoming Seminarsen-us2024-03-28T19:16:20-04:00https://sites.math.duke.edu/mcal2024-01-01T12:00:00-05:002dailyThe Linear Algebra of Quantum Mechanics: Look Maw, an Eigenvalue!
https://sites.math.duke.edu/mcal?abstract-3084
<a href="http://www.math.duke.edu/~msilvers/">Michael Silverstein</a> (Duke University Department of Mathematics)1999-09-03T16:00:00-04:003084Graduate-FacultyGraduate/Faculty SeminarFri, 03 Sep 1999 16:00:00 EDTFall, 1999Fri, 03 Sep 1999 17:00:00 EDTFriday, September 3, 1999, 4:00pm120 PhysicsOn the Optimality of the OGY Control Scheme
https://sites.math.duke.edu/mcal?abstract-3134
Bogdan Epureanu (Duke University)1999-09-10T14:15:00-04:003134CNCSCNCS SeminarFri, 10 Sep 1999 15:15:00 EDTFall, 1999Fri, 10 Sep 1999 14:15:00 EDTFriday, September 10, 1999, 2:15pm05 PhysicsScissors Congruence
https://sites.math.duke.edu/mcal?abstract-3085
If two polygons in the plane can be cut up into congruent pieces, they have the same area. It has been long known that the converse is also true. (This is a good exercise which will be solved in the talk.) Likewise, in three dimensions, two polyhedra have the same volume if they can be decomposed into congruent pieces. Is the converse true? This was one of the problems Hilbert posed at the end of the 19th century. Dehn gave a clever solution soon after Hilbert posed the problem which has lead to important connections with number theory and algebra. I'll explain what "scissors congruence" problems are and give a brief idea of their connections to algebra.<a href="http://www.math.duke.edu/faculty/hain/">Richard Hain</a> (Duke University Department of Mathematics)1999-09-10T16:00:00-04:003085Graduate-FacultyGraduate/Faculty Seminar120 PhysicsFriday, September 10, 1999, 4:00pmFall, 1999Fri, 10 Sep 1999 16:00:00 EDTFri, 10 Sep 1999 17:00:00 EDTTBA
https://sites.math.duke.edu/mcal?abstract-3135
Dr. David Adams (Hematology and Medical Oncology, Duke University)1999-09-14T14:15:00-04:003135CNCSCNCS Seminar05 PhysicsTuesday, September 14, 1999, 2:15pmFall, 1999Tue, 14 Sep 1999 14:15:00 EDTTue, 14 Sep 1999 15:15:00 EDTIntegers in the Gromov-Witten Theory of 3-folds
https://sites.math.duke.edu/mcal?abstract-3129
Abstract: Gopakumar and Vafa have proposed a formula for the Gromov-Witten
invariants of Calabi-Yau 3 folds in terms of numbers of BPS states. Part
of this formula is explained by higher genus multiple covers and collapsed
contributions in Gromov-Witten theory. The mathematical analysis leads to
a direct generalization of Gopakumar and Vafa's formula to an integral
structure for arbitrary 3 folds. I will discuss a mathematical approach
to these questions via integrals over the moduli space of stable curves.<a href="http://www.math.caltech.edu/people/profs.html">Rahul Pandharipande</a> (Cal Tech)1999-09-14T16:00:00-04:003129geometry/topologystring theoryGeometry and String Theory Seminar120 PhysicsTuesday, September 14, 1999, 4:00pmTue, 14 Sep 1999 17:00:00 EDTTue, 14 Sep 1999 16:00:00 EDTFall, 1999Holography in the Non-Critical Superstring
https://sites.math.duke.edu/mcal?abstract-3121
A ``non-critical superstring'' is a superstring in a background containing a linearly-varying dilaton. It is argued that a class of such vacua is holographically related to a (non-gravitational) theory obtained by studying string theory on a singular Calabi-Yau manifold, in the limit of vanishing string coupling. Adding fundamental strings at a two-dimensional singularity leads to conformal field theories dual to a class of superstring vacua with an AdS<sub>3</sub> factor. Some four-dimensional singularities are related to a theory on a NS5 brane wrapped around a Riemann surface, which is relevant in the realization of four-dimensional gauge theories via branes.Oskar Pelc (University of Chicago)1999-09-15T13:00:00-04:003121string theoryString Theory SeminarWednesday, September 15, 1999, 1:00pm246 PhysicsWed, 15 Sep 1999 14:00:00 EDTFall, 1999Wed, 15 Sep 1999 13:00:00 EDTFrames: Non-Orthogonal Expansions
https://sites.math.duke.edu/mcal?abstract-3081
Given a function, f, in a (separable) Hilbert space, H, we often wish to expand it in terms of simpler functions, for example sines and cosines in elementary Fourier analysis or orthonormal bases in more general settings. Frames provide another method of doing this and relax the condition of orthogonality. This is useful in the context of wavelets, where the construction of an orthonormal basis may be difficult. However, in such cases, frames provide alternate methods.<a href="http://www.math.duke.edu/~bihari/">Jonathan Bihari</a> (Duke University Department of Mathematics)1999-09-17T16:00:00-04:003081Graduate-FacultyGraduate/Faculty SeminarFall, 1999Fri, 17 Sep 1999 16:00:00 EDTFri, 17 Sep 1999 17:00:00 EDT120 PhysicsFriday, September 17, 1999, 4:00pmTBA
https://sites.math.duke.edu/mcal?abstract-3138
Dr. Fred Nijhout (Zoology, Duke University)1999-09-21T14:15:00-04:003138CNCSCNCS Seminar05 PhysicsTuesday, September 21, 1999, 2:15pmTue, 21 Sep 1999 14:15:00 EDTFall, 1999Tue, 21 Sep 1999 15:15:00 EDTHolomorphic Gerbes and Field Theory
https://sites.math.duke.edu/mcal?abstract-3149
Jean-Luc Brylinski (Pennsylvania State University)1999-09-21T16:00:00-04:003149geometry/topologystring theoryGeometry and String Theory SeminarTuesday, September 21, 1999, 4:00pm120 PhysicsTue, 21 Sep 1999 16:00:00 EDTFall, 1999Tue, 21 Sep 1999 17:00:00 EDTtracer flow in random porous media
https://sites.math.duke.edu/mcal?abstract-3185
I will explain some basic concepts for fluid flow in porous
media, go through some details about the 3D streamline simulator and SGSIM
(Sequential Gaussian SIMulation) for generating random permeability fields
under multiGaussian assumption.Zhuoxin Bi 1999-09-22T16:00:00-04:003185CMSMDC (KDI)CMSMDC (KDI) SeminarWed, 22 Sep 1999 16:00:00 EDTFall, 1999Wed, 22 Sep 1999 17:00:00 EDT120 PhysicsWednesday, September 22, 1999, 4:00pmQuantization of Orbits and Twisted Differential Operators
https://sites.math.duke.edu/mcal?abstract-3151
Ranee Brylinski (Pennsylvania State University)1999-09-22T16:00:00-04:003151geometry/topologyGeometry/Topology SeminarFall, 1999Wed, 22 Sep 1999 16:00:00 EDTWed, 22 Sep 1999 17:00:00 EDTWednesday, September 22, 1999, 4:00pm216 PhysicsThe Combinatorial Laplacian
https://sites.math.duke.edu/mcal?abstract-3119
The combinatorial laplacian is a method for computing the rational
homology of an algebraic or simplicial complex. Although the method
is quite old, it has recently been applied with success to a number of
problems in algebraic combinatorics. We will survey the method and
describe some of these recent applications.Phil Hanlon (University of Michigan)1999-09-23T16:00:00-04:003119geometry/topologyGeometry/Topology SeminarThursday, September 23, 1999, 4:00pm120 PhysicsThu, 23 Sep 1999 17:00:00 EDTThu, 23 Sep 1999 16:00:00 EDTFall, 1999Flow in Porous Media
https://sites.math.duke.edu/mcal?abstract-3126
I'll demonstrate some simple flow in porous media in a contraption that
looks like a large ant farm, and describe the basic mathematical models.
Then I'll talk about what we know and don't know when we work on real
problems. I'll briefly describe some numerical methods for solving
porous flow problems, and indicate how these can be used to help us
determine the unknowns. By the end of the talk, the students should have
some idea of what the KDI project is about, and how they might get
involved.<a href="http://www.math.duke.edu/faculty/trangenstein/">John Trangenstein</a> (Duke University Department of Mathematics)1999-09-24T16:00:00-04:003126Graduate-FacultyGraduate/Faculty Seminar120 PhysicsFriday, September 24, 1999, 4:00pmFri, 24 Sep 1999 17:00:00 EDTFri, 24 Sep 1999 16:00:00 EDTFall, 1999Boundary Integral Methods for Water Waves
https://sites.math.duke.edu/mcal?abstract-3172
We discuss numerical methods for time-dependent water waves
and the analysis needed to prove the convergence of properly designed
versions to the actual solution. Methods in wide use are based on
singular integrals arising from potential theory. The water surface
is tracked by points which move with the fluid velocity. The velocity
is determined from an integral equation on the surface. After reviewing
the equations of motion, we will formulate the problem in boundary
integrals and discuss some of the numerical issues. A central
concern is the efficient computation of singular integrals
such as single layer potentials on a surface. The approach
here is to regularize the singularity, use a standard
quadrature, and add a simple local correction.
For the stability estimates, mapping properties of the discrete
integral operators are used which are found by treating the
sums as discrete versions of pseudodifferential operators.<a href="http://www.math.duke.edu/faculty/beale">J. Thomas Beale</a> (Duke University)1999-09-27T16:00:00-04:003172applied math and analysisApplied Math SeminarMonday, September 27, 1999, 4:00pm120 PhysicsMon, 27 Sep 1999 17:00:00 EDTMon, 27 Sep 1999 16:00:00 EDTFall, 1999TBA
https://sites.math.duke.edu/mcal?abstract-3139
Dr. David Adams (Hematology and Medical Oncology, Duke University)1999-09-28T14:15:00-04:003139CNCSCNCS SeminarTuesday, September 28, 1999, 2:15pm05 PhysicsTue, 28 Sep 1999 15:15:00 EDTFall, 1999Tue, 28 Sep 1999 14:15:00 EDTOn the Topology of Canonical Singularities (at UNC)
https://sites.math.duke.edu/mcal?abstract-3183
Canonical singularities, introduced and studied by Miles Reid,
arise as singularities of the canonical model of a complex projective
variety of general type. Canonical surface singularities are either
non-singular points or DuVal singularities (also known as rational
double points, or ADE singularities, or simple singularities). In
dimension 3 the situation is much harder, the class of canonical
3-fold singularities has yet to reach a complete classification.
After discussing some general ideas about canonical singularities,
I will specialize to the case of a hypersurface X in the complex
four-space, having an isolated canonical singularity. It is known
that, although a minimal model Y of X is not unique in general, some
of its invariants, for instance the integer cohomology groups, are
independent of choices. I will present some methods of determining
the Betti numbers of Y, and illustrate these methods in a few
examples.Mirel Caibar 1999-09-28T16:00:00-04:003183geometry/topologyUNC Chapel Hill Geometry/Topology SeminarTuesday, September 28, 1999, 4:00pmat UNCTue, 28 Sep 1999 16:00:00 EDTFall, 1999Tue, 28 Sep 1999 17:00:00 EDTTracer Flow in Porous Media II
https://sites.math.duke.edu/mcal?abstract-3198
This is part II of an introductory talk on flow in porous media. Part I
covered basic physical concepts, development of the flow equations and
standard discretization schemes for the pressure equation.
Part II will cover streamtube methods for the conservation law in
incompressible flow, generation of random permeability fields and issues
in solving inverse problems to discover the permeability/porosity from
flow data.Zhuoxin Bi (Mathematics, Duke)1999-09-29T16:00:00-04:003198CMSMDC (KDI)CMSMDC (KDI) Seminar120 PhysicsWednesday, September 29, 1999, 4:00pmWed, 29 Sep 1999 17:00:00 EDTFall, 1999Wed, 29 Sep 1999 16:00:00 EDTMy Thesis and Why It's Not Done Yet
https://sites.math.duke.edu/mcal?abstract-3098
<a href="http://www.math.duke.edu/~taal/">Laura Taalman</a> (Duke University Department of Mathematics)1999-10-01T16:00:00-04:003098Graduate-FacultyGraduate/Faculty Seminar120 PhysicsFriday, October 1, 1999, 4:00pmFri, 01 Oct 1999 17:00:00 EDTFall, 1999Fri, 01 Oct 1999 16:00:00 EDTApplied Math Research: Math. Biology and Nonlinear Science
https://sites.math.duke.edu/mcal?abstract-3174
Michael Reed and Andrea Bertozzi (Duke University)1999-10-04T16:00:00-04:003174applied math and analysisApplied Math SeminarMonday, October 4, 1999, 4:00pm120 PhysicsFall, 1999Mon, 04 Oct 1999 16:00:00 EDTMon, 04 Oct 1999 17:00:00 EDTChange of Coordinates on the Large Phase Space of Quantum Cohomology
https://sites.math.duke.edu/mcal?abstract-3179
(Joint work with T. Kimura)
The Gromov-Witten invariants of a smooth, projective variety V, when
twisted by the tautological classes on the moduli space of stable
maps, give rise to a family of cohomological field theories and endow
the base of the family with coordinates. We compare the potential
functions associated to different choices of tautological classes, and
prove that they are related by an explicit change of coordinates that
resembles a change of basis on the ring of symmetric functions. This
generalizes a result of Kaufmann--Manin--Zagier and Manin--Zograf who
studied the case where V is a point.Sasha Kabonov (ETH Zuerich)1999-10-05T16:00:00-04:003179geometry/topologyGeometry/Topology Seminar120 PhysicsTuesday, October 5, 1999, 4:00pmTue, 05 Oct 1999 17:00:00 EDTTue, 05 Oct 1999 16:00:00 EDTFall, 1999TBA
https://sites.math.duke.edu/mcal?abstract-3200
Herbie Lee (ISDS, Duke)1999-10-06T16:00:00-04:003200CMSMDC (KDI)CMSMDC (KDI) SeminarWednesday, October 6, 1999, 4:00pm120 PhysicsFall, 1999Wed, 06 Oct 1999 16:00:00 EDTWed, 06 Oct 1999 17:00:00 EDTPerverse sheaves on triangulated spaces and Koszul duality
https://sites.math.duke.edu/mcal?abstract-3117
Maxim Vybornov (Duke University)1999-10-06T16:00:00-04:003117geometry/topologyGeometry/Topology SeminarFall, 1999Wed, 06 Oct 1999 16:00:00 EDTWed, 06 Oct 1999 17:00:00 EDT216 PhysicsWednesday, October 6, 1999, 4:00pmNo meeting.
https://sites.math.duke.edu/mcal?abstract-3122
Mary Pugh (University of Pennsylvania)1999-10-07T16:00:00-04:003122string theoryString Theory SeminarThu, 07 Oct 1999 16:00:00 EDTFall, 1999Thu, 07 Oct 1999 17:00:00 EDTThursday, October 7, 1999, 4:00pm120 PhysicsTBA
https://sites.math.duke.edu/mcal?abstract-3141
Dr. Shane Richards (Zoology, Duke University)1999-10-12T14:15:00-04:003141CNCSCNCS SeminarFall, 1999Tue, 12 Oct 1999 14:15:00 EDTTue, 12 Oct 1999 15:15:00 EDTTuesday, October 12, 1999, 2:15pm05 PhysicsDipole Flow Tests with Tracers
https://sites.math.duke.edu/mcal?abstract-3203
We propose a new aquifer characterization test,
{\sl the dipole-flow test with a tracer} (DFTT), and develop its
interpretation methodology. Combining the dipole-flow test (DFT) and a tracer
test, the DFTT is a single-borehole, forced-gradient tracer test.
The DFTT device isolates an injection and an extraction chamber
in a well with inflatable packers, and utilizes a small pump to create a
dipole-flow pattern. After a steady-state flow field is reached and the
pumping rate and chamber drawdowns are measured, a tracer is released into
the injection chamber, and the concentration breakthrough curve is
recorded in the extraction chamber. We use a streamtube modeling approach
to semi-analytically simulate the tracer transport in a DFTT, conducted in a
homogeneous aquifer with no skin zone around the well, and determine the
necessary relationships for estimating the longitudinal dispersivity as
well as the radial and vertical hydraulic conductivities. The arrival time
of the peak concentration is linearly related to the anisotropy ratio, and
the arrival time of the tracer front is related to the longitudinal
dispersivity. We present data from preliminary DFTTs conducted with Rhodamine
WT as a tracer at the Lizzie Field Site near Greenville, North Carolina.
Our results demonstrate that this single-borehole tracer test is feasible
and that its estimates of dispersivity are consistent with those reported in
literature whereas its estimates of hydraulic conductivities are approximately
an order of magnitude higher than those obtained from a flowmeter test.
The sorption of RWT and its composition of two differently sorbing isomers
complicates the nature of the DFTT breakthrough curve and its
interpretation. The use of a conservative tracer, such as bromide, will
eliminate this complication. The skin effects readily manifest themselves
in the DFTT breakthrough curve as as spurious and/or recirculated peaks.
The presented interpretation methodology applies to cases with
insignificant skin effects.Doug Sutton (Civil and Environmental Engineering, Duke)1999-10-13T16:00:00-04:003203CMSMDC (KDI)CMSMDC (KDI) Seminar120 PhysicsWednesday, October 13, 1999, 4:00pmWed, 13 Oct 1999 17:00:00 EDTWed, 13 Oct 1999 16:00:00 EDTFall, 1999Existence and Properties of Spatiotemporal Chaos in a 2D Excitable Medium
https://sites.math.duke.edu/mcal?abstract-3234
Henry Greenside (Dept of Physics, Duke Univ)1999-10-13T16:00:00-04:003234mathematical biologyMathematical Biology Seminar205 PhysicsWednesday, October 13, 1999, 4:00pmFall, 1999Wed, 13 Oct 1999 16:00:00 EDTWed, 13 Oct 1999 17:00:00 EDTD-Branes on Calabi-Yau Threefolds
https://sites.math.duke.edu/mcal?abstract-3132
D-branes on Calabi-Yau threefolds are interesting both as alternative
probes of quantum geometry, and as nontrivial realizations of gauge
theories with four supercharges. Of course, these issues are not
independent.
In this talk I will briefly discuss the former by describing and
characterizing D-brane states at the Gepner point in the moduli space
of the quintic. I will then use such D-branes to realize
d=4 N=1 SUSY gauge theories, and discuss the computation of the
superpotential of these theories, particularly for those realized
by D6-branes wrapped around special Lagrangian submanifolds of the
threefold. I will close with some speculations on the implications of
mirror symmetry for these superpotentials.Albion Lawrence (IAS Princeton)1999-10-14T16:00:00-04:003132string theoryString Theory SeminarFall, 1999Thu, 14 Oct 1999 16:00:00 EDTThu, 14 Oct 1999 17:00:00 EDTThursday, October 14, 1999, 4:00pm120 PhysicsSemistability of Induced Bundles Under a Low Height Representation
https://sites.math.duke.edu/mcal?abstract-3207
For a connected reductive algebraic group $G$, over an algebraically
closed field $k$ of charecteristic $p>0$, the semisimplicity and the
semistability of induced budlles are closely related with the heights
of dominant integral weights occuring there. The height of a weight
$ht(\lambda)$ is the sum of the coefficients of an expression as sum
simple roots. A representation is low height if every weight $\lambda$
occuring in $V$ satisfies $2ht(\lambda)<p$. In fact we prove:
{\bf THEOREM:} Let $G\to SL(V)$ is a {\em low height representation}.
Then for every normal projective variety $X$ with an ample line bundle
$M$, and for every pricipal $G$-bundle, $E$, which is semistable with
respect $M$, the induced pricipal bundle $E(SL(V))$ is also semistable.
This result is also useful in constructing the moduli of pricipal $G$
bundles in positive charecteristic as the aboove gives a boundedness for
the principal $G$-bundles. We also have the following converse:
{\bf THEOREM:} Let $G$ be an almost simple group, $p>\gamma(G)$ and $V$ a
representation not of low height. Then there exists a curve $X$ and a
semistable $G$-bundle on $X$ such that the induced principal bundle
$E(SL(V))$ is not semistable.
Moreover we also a complete reducibility result for non-reduecd groups
which occur as stabilizers of vectors under low height representations.
This results imply that we can have also a polystability (i.e., stable
bundles inducing direct sum of stable bundles) result. As another
application is to get Luna's etal slice theorem in positive charecteristic
for low height representations.(at UNC) A.J. Parameswaran (T.I.F.R.--Bombay)1999-10-15T15:00:00-04:003207geometry/topologyUNC Algebraic Geometry TalkPhillips Hall, UNCFriday, October 15, 1999, 3:00pmFri, 15 Oct 1999 16:00:00 EDTFri, 15 Oct 1999 15:00:00 EDTFall, 1999Index Theory and Supersymmetric Quantum Mechanics
https://sites.math.duke.edu/mcal?abstract-3087
<a href="http://www.math.duke.edu/faculty/stern/">Mark Stern</a> (Duke University Department of Mathematics)1999-10-15T16:00:00-04:003087Graduate-FacultyGraduate/Faculty SeminarFri, 15 Oct 1999 17:00:00 EDTFri, 15 Oct 1999 16:00:00 EDTFall, 1999120 PhysicsFriday, October 15, 1999, 4:00pmMathematics of Sea Ice
https://sites.math.duke.edu/mcal?abstract-3158
Sea ice undergoes a marked transition in its transport properties
at a critical temperature of around -5 C. Above this temperature,
the sea ice is porous, allowing percolation of brine, sea water,
nutrients, biomass, and heat through the ice. In the Antarctic,
this critical behavior plays a particularly important role in
air-sea-ice interactions, mixing in the upper ocean, in the
life cycles of algae living in the sea ice, and in the
interpretation of remote sensing data on the sea ice pack.
Recently we have applied percolation theory to model the transition
in the transport properties of sea ice. We give an overview of these
results, and how they explain data we have taken in the Antarctic.
We will also describe recent work in developing inverse algorithms
for recovering the physical properties of sea ice remotely
through electromagnetic means, and how percolation processes
come into play. At the conclusion of the talk, we will show
a short video on a recent winter expedition into the Antarctic
sea ice pack.<a href="http://www.math.utah.edu/">Ken Golden</a> (University of Utah)1999-10-18T16:00:00-04:003158applied math and analysisApplied Math SeminarMonday, October 18, 1999, 4:00pm120 PhysicsFall, 1999Mon, 18 Oct 1999 16:00:00 EDTMon, 18 Oct 1999 17:00:00 EDTTBA
https://sites.math.duke.edu/mcal?abstract-3143
<a href="http://mdennin@uci.edu">Dr. Michael Dennin</a> (UC-Irvine)1999-10-19T14:15:00-04:003143CNCSCNCS SeminarTuesday, October 19, 1999, 2:15pm05 PhysicsFall, 1999Tue, 19 Oct 1999 14:15:00 EDTTue, 19 Oct 1999 15:15:00 EDTAnalysis of Delay-Differential Equations and Its Impact on Estimating Kinetic Parameters Associated with HIV Infection
https://sites.math.duke.edu/mcal?abstract-3219
Patrick Nelson (Dept of Mathematics, Duke Univ)1999-10-20T16:00:00-04:003219mathematical biologyMathematical Biology SeminarWednesday, October 20, 1999, 4:00pm205 PhysicsFall, 1999Wed, 20 Oct 1999 16:00:00 EDTWed, 20 Oct 1999 17:00:00 EDTCompactifications with G-Flux
https://sites.math.duke.edu/mcal?abstract-3196
Savdeep Sethi (IAS Princeton)1999-10-21T16:00:00-04:003196string theoryString Theory SeminarThursday, October 21, 1999, 4:00pm120 PhysicsThu, 21 Oct 1999 17:00:00 EDTThu, 21 Oct 1999 16:00:00 EDTFall, 1999Voronoi Diagrams and How to Compute Them
https://sites.math.duke.edu/mcal?abstract-3088
I'll explain what the Voronoi diagram of a (finite) set of points in the
plane is, and what it's good for, anyway. Then I'll go through a variety
of different algorithms for actually computing it.<a href="http://www.math.duke.edu/~annec/">Anne Collins</a> (Duke University Department of Mathematics)1999-10-22T16:00:00-04:003088Graduate-FacultyGraduate/Faculty SeminarFri, 22 Oct 1999 16:00:00 EDTFall, 1999Fri, 22 Oct 1999 17:00:00 EDT120 PhysicsFriday, October 22, 1999, 4:00pmThe Immersed Interface Method:
A Numerical Approach for Interface Problems
https://sites.math.duke.edu/mcal?abstract-3160
Many physical problems involve interfaces. Examples include phase transition
problems where the interface separates the solid and liquid regions, bubble
simulation, Hele-Shaw flow, composite materials, and many other important
physical phenomena. Mathematically, interface problems usually lead to
differential equations whose input data and solutions have discontinuities
or non-smoothness across interfaces. As a result, many standard numerical
schemes do not work or work poorly for interface problems.
This is an introductory talk about the interface problems and our immersed
interface method. Through some simple examples, I will try to explain the
problems of our interest and related background information. Then I will
present our method for some typical model problems in two dimensions. Our
method can handle both discontinuous coefficients and singular sources.
The main idea is to incorporate the known jumps in the solution and its
derivatives into the finite difference scheme, obtaining a modified scheme
on the uniform grid for quite arbitrary interfaces. The second part of the
talk will focus on applications of the methods combined with the the level
set method for moving interface problems: including the Stokes flow with
different surface tension, the simulation of Hele-Shaw flow, and computation
of crystal growth.<a href="http://www4.ncsu.edu/~zhilin/">Zhilin Li</a> (North Carolina State University)1999-10-25T16:00:00-04:003160applied math and analysisApplied Math Seminar120 PhysicsMonday, October 25, 1999, 4:00pmMon, 25 Oct 1999 17:00:00 EDTMon, 25 Oct 1999 16:00:00 EDTFall, 19993D Heart Simulations
https://sites.math.duke.edu/mcal?abstract-3145
Dr. Flavio Fenton 1999-10-26T14:15:00-04:003145CNCSCNCS SeminarTue, 26 Oct 1999 15:15:00 EDTTue, 26 Oct 1999 14:15:00 EDTFall, 1999Tuesday, October 26, 1999, 2:15pm05 PhysicsFiltrations on Completions of Arithmetic Fundamental Groups
https://sites.math.duke.edu/mcal?abstract-3232
Richard Hain (Duke University)1999-10-26T16:00:00-04:003232geometry/topologyGeometry/Topology SeminarTuesday, October 26, 1999, 4:00pm120 PhysicsTue, 26 Oct 1999 17:00:00 EDTTue, 26 Oct 1999 16:00:00 EDTFall, 1999TBA
https://sites.math.duke.edu/mcal?abstract-3223
Gary Pope (CPGE, UT Austin)1999-10-27T16:00:00-04:003223CMSMDC (KDI)CMSMDC (KDI) SeminarWednesday, October 27, 1999, 4:00pm120 PhysicsFall, 1999Wed, 27 Oct 1999 16:00:00 EDTWed, 27 Oct 1999 17:00:00 EDTA Mathematical Model to Study the Effects of Drug Resistance and Vasculature on the Response of Solid Tumors to Chemotherapy
https://sites.math.duke.edu/mcal?abstract-3221
Tracy Jackson (Dept of Mathematics, Duke Univ)1999-10-27T16:00:00-04:003221mathematical biologyMathematical Biology SeminarWed, 27 Oct 1999 17:00:00 EDTWed, 27 Oct 1999 16:00:00 EDTFall, 1999205 PhysicsWednesday, October 27, 1999, 4:00pmNo meeting.
https://sites.math.duke.edu/mcal?abstract-3156
Mary Pugh (University of Pennsylvania)1999-10-28T16:00:00-04:003156string theoryString Theory Seminar120 PhysicsThursday, October 28, 1999, 4:00pmThu, 28 Oct 1999 16:00:00 EDTFall, 1999Thu, 28 Oct 1999 17:00:00 EDTMathematics in the Pharmaceutical and Biotech Industries: What Jobs Are Out There, and How to Get Your Foot in the Door
https://sites.math.duke.edu/mcal?abstract-3090
<a href="http://www.vpharm.com/">Mary Beth Fisher</a> (Vector Pharmaceuticals)1999-10-29T16:00:00-04:003090Graduate-FacultyGraduate/Faculty Seminar120 PhysicsFriday, October 29, 1999, 4:00pmFri, 29 Oct 1999 17:00:00 EDTFall, 1999Fri, 29 Oct 1999 16:00:00 EDTBoundary Effects in Controlled Rayleigh-Benard Convection
https://sites.math.duke.edu/mcal?abstract-3162
We investigate the effect of finite horizontal boundary properties on
the critical Rayleigh and wave numbers for controlled Rayleigh-Benard
convection in an infinite horizontal domain. Specifically, we examine
boundary thickness, thermal diffusivity and thermal conductivity. Our
control method is through perturbation of the lower boundary heat
flux. A linear differential-proportional control law uses the local
amplitude of a shadowgraph to actively distribute the lower boundary
heat flux. Realistic boundary conditions for laboratory experiments
are selected. Through linear stability analysis and experiment we
examine the important boundary properties and make predictions of the
properties necessary for successful control experiments. A surprising
finding of this work is that for certain realistic parameter ranges,
one may find an isola to time-dependent convection as the primary
bifurcation.<a href="http://www.duke.edu/~leh/lhowle.html">Laurens E. Howle</a> (Duke University, Mech Eng and Mat Sci Dept)1999-11-01T16:00:00-05:003162applied math and analysisApplied Math SeminarMon, 01 Nov 1999 17:00:00 ESTMon, 01 Nov 1999 16:00:00 ESTFall, 1999Monday, November 1, 1999, 4:00pm120 PhysicsNetwork I/O with Trapeze/Myrinet
https://sites.math.duke.edu/mcal?abstract-3247
Jeff Chase (Duke Computer Science)1999-11-03T16:00:00-05:003247CMSMDC (KDI)CMSMDC (KDI) SeminarWed, 03 Nov 1999 17:00:00 ESTFall, 1999Wed, 03 Nov 1999 16:00:00 ESTWednesday, November 3, 1999, 4:00pm120 PhysicsThis Week
https://sites.math.duke.edu/mcal?abstract-3249
No Talk 1999-11-03T16:00:00-05:003249mathematical biologyMathematical Biology SeminarWednesday, November 3, 1999, 4:00pm205 PhysicsFall, 1999Wed, 03 Nov 1999 16:00:00 ESTWed, 03 Nov 1999 17:00:00 ESTOn a Conjecture of Deligne and Ihara
https://sites.math.duke.edu/mcal?abstract-3227
Richard Hain (Duke University)1999-11-03T16:00:00-05:003227geometry/topologyGeometry/Topology SeminarWed, 03 Nov 1999 16:00:00 ESTFall, 1999Wed, 03 Nov 1999 17:00:00 EST216 PhysicsWednesday, November 3, 1999, 4:00pmM-Theory, Topological Strings and Spinning Black Holes
https://sites.math.duke.edu/mcal?abstract-3192
We consider M-theory compactifications on Calabi-Yau threefolds.
The recently discovered connection between the BPS states of wrapped M2-branes
and the topological string amplitudes on the threefold is used both as a
tool to compute topological string amplitudes at higher genera as well as to
unravel the degeneracies and quantum numbers of BPS states.
Moduli spaces of k-fold symmetric products of the wrapped M2 brane play a
crucial role. We also show that the topological string partition function
is the Calabi-Yau version of the elliptic genus of the symmetric product
of K3's and use the macroscopic entropy of spinning black holes in 5
dimensions to obtain new predictions for the asymptotic growth of the
topological string amplitudes at high genera.Albrecht Klemm (IAS Princeton)1999-11-04T16:00:00-05:003192string theoryString Theory Seminar at UNC-CHThu, 04 Nov 1999 17:00:00 ESTFall, 1999Thu, 04 Nov 1999 16:00:00 ESTPhillips Hall (UNC-CH)Thursday, November 4, 1999, 4:00pmTGF-Mediated Oscillations
https://sites.math.duke.edu/mcal?abstract-3092
<a href="http://www.math.duke.edu/~doldson/">Darren Oldson</a> (Duke University Department of Mathematics)1999-11-05T16:00:00-05:003092Graduate-FacultyGraduate/Faculty SeminarFriday, November 5, 1999, 4:00pm120 PhysicsFri, 05 Nov 1999 17:00:00 ESTFri, 05 Nov 1999 16:00:00 ESTFall, 1999Consuming, Grouping and Coexisting: Resource-Mediated Aggregation
https://sites.math.duke.edu/mcal?abstract-3164
A general consumer--resource model assuming discrete consumers and a
continuously structured resource is examined. We study two foraging
behaviors, which lead to fixed and flexible patch residence times,
in conjunction with a simple consumer energetics model linking resource
consumption, foraging behavior, and metabolic costs. Results indicate a
single evolutionarily stable foraging strategy for fixed and flexible
foraging in a nonspatial environment, but flexible foraging in a spatial
environment leads to consumer grouping, which affects the resource
distribution such that no single foraging strategy can exclude all
other strategies. This evolutionarily stable coexistence of multiple
foraging strategies may help explain a dichotomous pattern observed
in a wide variety of natural systems.<a href="http://www.zoology.duke.edu/wilson/">Will Wilson</a> (Duke University, Dept. of Zoology)1999-11-08T16:00:00-05:003164applied math and analysisApplied Math SeminarMon, 08 Nov 1999 16:00:00 ESTFall, 1999Mon, 08 Nov 1999 17:00:00 ESTMonday, November 8, 1999, 4:00pm120 PhysicsThe Hodge Star Operator on Schubert Forms
https://sites.math.duke.edu/mcal?abstract-3181
The Hodge star operator acts on the space of differential forms on a
hermitian complex manifold X and induces an action on the harmonic forms,
hence on the cohomology of X. I will give explicit combinatorial formulas
for this action when X is a compact hermitian symmetric space, such as
a Grassmannian, and discuss connections of this problem with the Lefschetz
theory on X. I will also talk about the motivation for this work, which
came from a conjecture in Arakelov geometry.
The speaker arrives Sat. Nov. 6 and departs Tuesday Nov. 9Harry Tamvakis (University of Pennsylvania)1999-11-09T16:00:00-05:003181geometry/topologyGeometry/Topology SeminarTue, 09 Nov 1999 16:00:00 ESTFall, 1999Tue, 09 Nov 1999 17:00:00 EST120 PhysicsTuesday, November 9, 1999, 4:00pmThe Large N Limit of Field Theories and Gravity
https://sites.math.duke.edu/mcal?abstract-3216
<a href="http://www.physics.harvard.edu/fac_staff/theoretical.html#maldacena">Juan Maldacena</a> (Harvard University)1999-11-10T15:00:00-05:003216string theoryHigh Energy Theory Seminar at UNC-CHWednesday, November 10, 1999, 3:00pmPhillips Hall (UNC-CH) Room 258Wed, 10 Nov 1999 15:00:00 ESTFall, 1999Wed, 10 Nov 1999 16:00:00 ESTThis Week
https://sites.math.duke.edu/mcal?abstract-3251
No Talk 1999-11-10T16:00:00-05:003251mathematical biologyMathematical Biology SeminarWednesday, November 10, 1999, 4:00pm205 PhysicsWed, 10 Nov 1999 17:00:00 ESTWed, 10 Nov 1999 16:00:00 ESTFall, 1999D-Instantons in the AdS/CFT Correspondence
https://sites.math.duke.edu/mcal?abstract-3123
A review of D-instantons in IIB superstring theory and their relation
to instantons in N=4 super-Yang-Mills via the AdS/CFT duality is given.
These methods are applied to conformal N=2 theories which can be realized
as orientifolds of IIB. Heterotic / type I' duality is used to calculate
D-instanton contributions exactly and relate them to Yang-Mills instanton
contributions, which can in principle be calculated by ADHM-calculus.Michael Gutperle (Harvard University)1999-11-11T16:00:00-05:003123string theoryString Theory Seminar at UNC-CHThu, 11 Nov 1999 17:00:00 ESTFall, 1999Thu, 11 Nov 1999 16:00:00 ESTPhillips Hall (UNC-CH)Thursday, November 11, 1999, 4:00pmSuperstring Compactification 101
https://sites.math.duke.edu/mcal?abstract-3093
Note different time!<a href="http://www.cgtp.duke.edu/~psa/">Paul Aspinwall</a> (Duke University Departments of Mathematics and Physics)1999-11-12T16:15:00-05:003093Graduate-FacultyGraduate/Faculty SeminarFri, 12 Nov 1999 17:15:00 ESTFall, 1999Fri, 12 Nov 1999 16:15:00 ESTFriday, November 12, 1999, 4:15pm120 PhysicsAllee Dynamics, Critical Phenomena and Species' Borders
https://sites.math.duke.edu/mcal?abstract-3294
Tim Keitt (National Center for Ecological Analysis and Synthesis)1999-11-16T14:15:00-05:003294CNCSCNCS SeminarTue, 16 Nov 1999 15:15:00 ESTTue, 16 Nov 1999 14:15:00 ESTFall, 199905 PhysicsTuesday, November 16, 1999, 2:15pmGopakumar-Vafa Invariants of Moduli Spaces of Holomorphic Curves and Integrality
https://sites.math.duke.edu/mcal?abstract-3225
In a remarkable paper, Gopakumar and Vafa have used M-theory to assign BPS
invariants to families of holomorphic curves which are believed
to yield the Gromov-Witten invariants. In this talk, techniques of
algebraic geometry are developed for calculating these invariants which
agree with mirror symmetry results in examples. The proper mathematical
context for complete generalization of these ideas appears to require
geometric invariant theory.Sheldon Katz (Oklahoma State University)1999-11-16T16:00:00-05:003225geometry/topologystring theoryGeometry and String Theory SeminarTue, 16 Nov 1999 17:00:00 ESTTue, 16 Nov 1999 16:00:00 ESTFall, 1999120 PhysicsTuesday, November 16, 1999, 4:00pmTBA
https://sites.math.duke.edu/mcal?abstract-3229
<a href="http://cmr.sph.unc.edu/CMR">Cass T. Miller</a> (UNC)1999-11-17T16:00:00-05:003229CMSMDC (KDI)CMSMDC (KDI) SeminarFall, 1999Wed, 17 Nov 1999 16:00:00 ESTWed, 17 Nov 1999 17:00:00 ESTWednesday, November 17, 1999, 4:00pm120 PhysicsModels and Mechanisms of Pigment Pattern Formation in Butterflies
https://sites.math.duke.edu/mcal?abstract-3255
Fred Nijhout (Dept of Zoology, Duke Univ)1999-11-17T16:00:00-05:003255mathematical biologyMathematical Biology Seminar205 PhysicsWednesday, November 17, 1999, 4:00pmWed, 17 Nov 1999 17:00:00 ESTWed, 17 Nov 1999 16:00:00 ESTFall, 1999On the geometry of Bochner-Kahler metrics
https://sites.math.duke.edu/mcal?abstract-3281
<a href="mailto:bryant@math.duke.edu">Robert Bryant</a> (Duke University)1999-11-17T16:00:00-05:003281geometry/topologyGeometry/Topology Seminar216 PhysicsWednesday, November 17, 1999, 4:00pmFall, 1999Wed, 17 Nov 1999 16:00:00 ESTWed, 17 Nov 1999 17:00:00 ESTSmall N 2D Gauge Theory and Small N Supersymmetry
https://sites.math.duke.edu/mcal?abstract-3187
We discuss aspects of the renormalization group flow of quiver gauge
theories in two dimensions, with little or no supersymmetry, in the
spirit of earlier work of Zamolodchikov on non-supersymmetric
Landau-Ginzburg theory. By using a variety of techniques including
analysis of chiral symmetries, identification of operators, and analysis
of perturbative gauge theory diagrams, we show that these theories can
(at least) be fine-tuned to flow to orbifold conformal field theory in
the infrared. This provides a linear sigma model description of string
backgrounds with no spacetime supersymmetry, whose applications and
limitations we begin to explore.<a href="http://www.slac.stanford.edu/slac/faculty/hepfaculty/silverstein.html">Eva Silverstein</a> (SLAC, Stanford)1999-11-18T16:00:00-05:003187string theoryString Theory SeminarThu, 18 Nov 1999 17:00:00 ESTThu, 18 Nov 1999 16:00:00 ESTFall, 1999120 PhysicsThursday, November 18, 1999, 4:00pmUndercompressive Fronts: Shocking (!) Behavior Leads to Fingerless Flows
https://sites.math.duke.edu/mcal?abstract-3086
Note: expect pretty computer pictures!<a href="http://www.math.duke.edu/~bertozzi">Andrea Bertozzi</a> (Duke University Department of Mathematics)1999-11-19T16:00:00-05:003086Graduate-FacultyGraduate/Faculty SeminarFriday, November 19, 1999, 4:00pm120 PhysicsFri, 19 Nov 1999 17:00:00 ESTFri, 19 Nov 1999 16:00:00 ESTFall, 1999The Role of Cardiac Tissue Structure in Reentry Induction: A Modeling Study
https://sites.math.duke.edu/mcal?abstract-3167
Most dangerous cardiac arrhythmia, ventricular
fibrillation (VF), is characterized by chaotic
electrical behavior of the tissue. At the onset
of the first, more organized stage of VF waves
of electric activity in the heart become reentrant
leading to fast irregular contraction.
Better understanding of the mechanisms underlying
early VF events will lead to more efficient treatment.
Reentry induction has been performed in several
experiments. We devise a model of cardiac
tissue and use it to obtain a close match to
the experimental results.
The model combines macroscopic and microscopic
properties of cardiac tissue.<a href="http://www.math.duke.edu/faculty/skouibine/">Kirill B. Skouibine</a> (Duke University)1999-11-22T16:00:00-05:003167applied math and analysisApplied Math SeminarMon, 22 Nov 1999 16:00:00 ESTFall, 1999Mon, 22 Nov 1999 17:00:00 EST120 PhysicsMonday, November 22, 1999, 4:00pmThe Spatiotemporal Dynamics of Generalized Tonic-Clonic Seizures
https://sites.math.duke.edu/mcal?abstract-3299
Andrew Krystal 1999-11-23T14:15:00-05:003299CNCSCNCS Seminar05 PhysicsTuesday, November 23, 1999, 2:15pmFall, 1999Tue, 23 Nov 1999 14:15:00 ESTTue, 23 Nov 1999 15:15:00 ESTThis Week
https://sites.math.duke.edu/mcal?abstract-3256
No Talk 1999-11-24T16:00:00-05:003256mathematical biologyMathematical Biology SeminarWed, 24 Nov 1999 16:00:00 ESTFall, 1999Wed, 24 Nov 1999 17:00:00 ESTWednesday, November 24, 1999, 4:00pm205 PhysicsNo meeting -- Thanksgiving break
https://sites.math.duke.edu/mcal?abstract-3115
Mary Pugh (University of Pennsylvania)1999-11-25T16:00:00-05:003115string theoryString Theory SeminarThu, 25 Nov 1999 16:00:00 ESTFall, 1999Thu, 25 Nov 1999 17:00:00 EST120 PhysicsThursday, November 25, 1999, 4:00pmTBA
https://sites.math.duke.edu/mcal?abstract-3304
Scott De Marchi 1999-11-30T14:15:00-05:003304CNCSCNCS SeminarFall, 1999Tue, 30 Nov 1999 14:15:00 ESTTue, 30 Nov 1999 15:15:00 ESTTuesday, November 30, 1999, 2:15pm05 PhysicsNo meeting of geom/top seminar
https://sites.math.duke.edu/mcal?abstract-3279
Mary Pugh (University of Pennsylvania)1999-11-30T16:00:00-05:003279geometry/topologyGeometry/Topology SeminarTue, 30 Nov 1999 17:00:00 ESTFall, 1999Tue, 30 Nov 1999 16:00:00 ESTTuesday, November 30, 1999, 4:00pm120 PhysicsOn Topological Equivalence and the "Hartman-Grobman" Theorem for Control Systems
https://sites.math.duke.edu/mcal?abstract-3287
Jean-Baptiste Pomet (INRIA-Sophia)1999-12-01T16:00:00-05:003287geometry/topologyGeometry/Topology SeminarWed, 01 Dec 1999 17:00:00 ESTWed, 01 Dec 1999 16:00:00 ESTFall, 1999Wednesday, December 1, 1999, 4:00pm120 PhysicsModels for Nonlinear Spatial Interactions in Reaction-Diffusion Problems
https://sites.math.duke.edu/mcal?abstract-3300
Tom Witelski (Duke University, Dept. of Mathematics)1999-12-01T16:00:00-05:003300mathematical biologyMathematical Biology Seminar205 PhysicsWednesday, December 1, 1999, 4:00pmWed, 01 Dec 1999 17:00:00 ESTFall, 1999Wed, 01 Dec 1999 16:00:00 ESTBranes, Supersymmetric Cycles and Deformed Instantons
https://sites.math.duke.edu/mcal?abstract-3124
Ruben Minasian (Yale University)1999-12-02T16:00:00-05:003124string theoryString Theory Seminar at UNC-CHFall, 1999Thu, 02 Dec 1999 16:00:00 ESTThu, 02 Dec 1999 17:00:00 ESTPhillips Hall (UNC-CH)Thursday, December 2, 1999, 4:00pmTBA
https://sites.math.duke.edu/mcal?abstract-3096
<a href="http://www.math.duke.edu/~trd1/">Ryan Deering</a> (Duke University Department of Mathematics)1999-12-03T16:00:00-05:003096Graduate-FacultyGraduate/Faculty Seminar120 PhysicsFriday, December 3, 1999, 4:00pmFri, 03 Dec 1999 16:00:00 ESTFall, 1999Fri, 03 Dec 1999 17:00:00 ESTAn Adaptive H-Refinement Finite Element For Solving Systems of Parabolic Partial Differential Equations in Three Space Dimensions
https://sites.math.duke.edu/mcal?abstract-3171
Adaptive methods for solving systems of partial differential equations
have become widespread. Robust
adaptive software for solving parabolic systems in one and two space
dimensions is now widely available.
Three spatial adaptive strategies and combinations thereof are
frequently employed: mesh refinement
(h-refinement); mesh motion (r-refinement); and order variation
(p-refinement). These adaptive
strategies are driven by a priori and a posteriori error estimates.
I will present an adaptive h-refinement finite element code in three
dimensions on structured grids.
These structured grids contain irregular nodes. Solution values at these
nodes are determined by
continuity requirements across element boundaries rather than by the
differential equations. The
differential-algebraic system resulting from the spatial discretization
is integrated using Linda
Petzold's multistep DAE code DASPK. The large linear systems resulting
from Newton's method applied to
nonlinear system of differential algebraic equations is solved using
preconditioned GMRES. In DASPK the
matrix-vector products needed by GMRES are approximated by a
``directional derivative''. Thus, the
Jacobian matrix need not be assembled. However, this approach is
inefficient. I have modified DASPK to
compute the matrix-vector product using stored Jacobian matrix. As in
the earlier version of DASPK,
DASSL, this matrix is kept for several time steps before being updated.
I will discuss appropriate
preconditioning strategies, including fast-banded preconditioners. In
three dimensions when using
multistep methods for time integration it is crucial to use a ``warm
restart'', that is, to restart the
dae solver at the current time step and order. This requires
interpolation of the history information.
The interpolation must be done in such a way that mode irregularity is
enforced on the new grid.
A posteriori error estimates on uniform grids can easily be generalized
from two-dimensional results
(Babuska and Yu showed that in the case of odd order elements, jumps
across elemental boundaries give
accurate estimates, and in the case of even order elements, local
parabolic systems must be solved to
obtain accurate estimates). Babuska's work can even be generalized to
meshes with irregular modes but
now they no longer converge to the true error (in the case of odd order
elements). I have developed a
new set of estimates that extend the work of Babuska to irregular meshes
and finite difference methods.
These estimates provide a posteriori error indicators in the finite
element context.
Several examples that demonstrate the effectiveness of the code will be
given.<a href="http://www.math.tulane.edu:80/~pkm/">Peter K. Moore</a> (Tulane University)1999-12-06T16:00:00-05:003171applied math and analysisApplied Math Seminar120 PhysicsMonday, December 6, 1999, 4:00pmFall, 1999Mon, 06 Dec 1999 16:00:00 ESTMon, 06 Dec 1999 17:00:00 ESTThe Strength and Flow Properties of Granular Matter Fluidized by Air Flow or Shear
https://sites.math.duke.edu/mcal?abstract-3147
Dr. Wolfgang Losert (Physics Department, Haverford College)1999-12-07T14:15:00-05:003147CNCSCNCS SeminarTue, 07 Dec 1999 15:15:00 ESTTue, 07 Dec 1999 14:15:00 ESTFall, 1999Tuesday, December 7, 1999, 2:15pm05 PhysicsMonodromy in Families of Abelian Varieties
https://sites.math.duke.edu/mcal?abstract-3245
The p-power torsion of a family of elliptic curves in characteristic p
defines a local system on the base space. Igusa shows that the
associated monodromy representation is maximal, in the sense that the
image of the fundamental group is the full automorphism group of a
fiber. I will discuss variants of this situation which can make the
group in question bigger (higher-dimensional abelian varieties),
smaller (with large endomorphism rings), or simply different (and no
physical p-torsion). I hope to interpret these results as statements
about certain differential equations.Jeff Achter 1999-12-07T16:00:00-05:003245geometry/topologyGeometry/Topology SeminarTue, 07 Dec 1999 17:00:00 ESTFall, 1999Tue, 07 Dec 1999 16:00:00 EST120 PhysicsTuesday, December 7, 1999, 4:00pmFun with Supersymmetric Three-Cycles
https://sites.math.duke.edu/mcal?abstract-3155
We study the physics of D6 branes wrapped on supersymmetric three-cycles
in type IIA string theory. In particular, we argue that although the
superpotential in the resulting field theories vanishes to all orders
in \alpha', nonperturbative contributions (from disk instantons) should
generically be present. We discuss how mirror symmetry can relate these
to tree-level sigma model computations in some circumstances.
We also present an illustration of the role that background closed
string moduli play in the brane worldvolume theory.<a href="http://www.stanford.edu/dept/physics/Faculty/kachru.shamit.shtml">Shamit Kachru</a> (SLAC, Stanford)1999-12-10T14:00:00-05:003155string theoryString Theory Seminar120 PhysicsFriday, December 10, 1999, 2:00pmFri, 10 Dec 1999 14:00:00 ESTFall, 1999Fri, 10 Dec 1999 15:00:00 ESTResearch in Undergraduate Mathematics Education: What is it and who cares?
https://sites.math.duke.edu/mcal?abstract-3094
<a href="http://galois.oxy.edu/mickey">Michael McDonald</a> (Occidental College Department of Mathematics)1999-12-10T15:15:00-05:003094Graduate-FacultyGraduate/Faculty SeminarFri, 10 Dec 1999 16:15:00 ESTFri, 10 Dec 1999 15:15:00 ESTFall, 1999Friday, December 10, 1999, 3:15pm120 PhysicsPerverse Sheaves on affine Grassmannians and Langlands Duality(after I. Mirkovic and K. Vilonen)
https://sites.math.duke.edu/mcal?abstract-3309
Maxim Vybornov (Duke University)1999-12-31T18:59:00-05:003309geometry/topologyGeometry/Topology SeminarFriday, December 31, 1999, 6:59pm120 PhysicsFri, 31 Dec 1999 18:59:00 ESTFall, 1999Fri, 31 Dec 1999 19:59:00 ESTDepartment [DELETED]
https://sites.math.duke.edu/mcal?abstract-12979
Dept. Faculty Meeting 2024-03-22T10:30:00-04:0012979Department of MathematicsR.BryantdeletedFri, 22 Mar 2024 11:30:00 EDTFri, 22 Mar 2024 10:30:00 EDTSpring, 2024Friday, March 22, 2024, 10:30amPhysics 119TBA [DELETED]
https://sites.math.duke.edu/mcal?abstract-12849
<a href="https://www.ihes.fr/~urbanik/">David Urbanik</a> (IHES)2024-03-29T13:30:00-04:0012849algebraic geometryAlgebraic Geometry SeminarFri, 29 Mar 2024 13:30:00 EDTSpring, 2024Fri, 29 Mar 2024 14:30:00 EDTdeletedZoom linkFriday, March 29, 2024, 1:30pmTBA [DELETED] --- CANCELED
https://sites.math.duke.edu/mcal?abstract-12874
<a href="https://spencerleslie.com/">Spencer Leslie</a> (Boston College, Mathematics)2024-04-10T15:15:00-04:0012874Number TheoryNumber Theory SeminarPhysics 119Wednesday, April 10, 2024, 3:15pmdeletedWed, 10 Apr 2024 15:15:00 EDTIntSpring, 2024Wed, 10 Apr 2024 15:15:00 EDTTBA [DELETED]
https://sites.math.duke.edu/mcal?abstract-12956
<a href="https://sites.google.com/view/jpark776/home">Jaemin Park</a> (University of Basel)2024-04-23T15:15:00-04:0012956Department of Mathematicsapplied math and analysisDepartment of Mathematics SeminardeletedTue, 23 Apr 2024 16:15:00 EDTSpring, 2024Tue, 23 Apr 2024 15:15:00 EDTPhysics 119Tuesday, April 23, 2024, 3:15pm [DELETED]
https://sites.math.duke.edu/mcal?abstract-12872
Mary Pugh (University of Pennsylvania)2024-05-11T11:00:00-04:0012872Department of MathematicsGraduation "SAVE THE DATE"deletedSat, 11 May 2024 14:00:00 EDTSpring, 2024Sat, 11 May 2024 11:00:00 EDTOnsiteSaturday, May 11, 2024, 11:00am