BEGIN:VCALENDAR
VERSION:2.0
METHOD:PUBLISH
PRODID:-//Mathematics Department//NONSGML mathical.php//EN
X-WR-CALNAME:Mathematics Department
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadebbc5@math.dartmouth.edu
DTSTART;TZID=America/New_York:20180914T153000
DTEND;TZID=America/New_York:20180914T163000
CATEGORIES:Math Colloquium
SUMMARY:Joseph Teran: Elastoplasticity Simulation with the Material
Point Method
DESCRIPTION: Hyperelastic constitutive models describe a wide range
of materials. Examples include biomechanical soft tissues like
muscle\, tendon\, skin etc. Elastoplastic materials consisting of a
hyperelastic constitutive model combined with a notion of stress
constraint (or feasible stress region) describe an even wider range
of materials. A very interesting class of these models arise from
frictional contact considerations. I will discuss some recent
results and examples in computer graphics and virtual surgery
applications. Examples include simulation of granular materials like
snow in Walt Disney's ``Frozen" as well as frictional contact
between thin elastic membranes and shells for virtual clothing
simulation. I will also discuss practical simulation of these
materials with some recent algorithmic modifications to the
Particle-In-Cell (PIC) technique\, the Material Point Method (MPM).
LOCATION:Kemeny 007
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadebc46@math.dartmouth.edu
DTSTART;TZID=America/New_York:20180914T190000
CATEGORIES:Prosser Lecture
SUMMARY:Joseph Teran: Snow Business: Scientific Computing in the
Movies and Beyond
DESCRIPTION:Abstract: New applications of scientific computing for
solid and fluid mechanics problems include simulation of virtual
materials in movie visual effects and virtual surgery. Both
disciplines demand physically realistic dynamics for materials like
water\, smoke\, fire\, and soft tissues. New algorithms are required
for each area. Teran will speak about the simulation techniques
required in these fields and will share some recent results
including: simulated surgical repair of biomechanical soft tissues\;
extreme deformation of elastic objects with contact\; high
resolution incompressible flow\; and clothing and hair dynamics. He
will also discuss a new algorithm used for simulating the dynamics
of snow in Disney’s animated feature film\, “Frozen”.
LOCATION:Kemeny 008
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadebc9a@math.dartmouth.edu
DTSTART;TZID=America/New_York:20180920T143000
DTEND;TZID=America/New_York:20180920T153000
CATEGORIES:Algebra and Number Theory Seminar
SUMMARY:Tyler Kelly: Equivalences of Toric Mirror Constructions
DESCRIPTION:Mirror Symmetry is a duality from string theory that
exchanges various geometric data between two spaces M and W which
are called 'mirrors' of each other. One foundational question
involves how one constructs the mirror given the first space. We
will describe one such construction for hypersurfaces in
weighted-projective spaces\, and then show how\, a priori\, it
doesn't seem perfectly self-consistent. We solve this though by
showing equivalences between the potential mirrors. We will finish
the talk with how this leads to results about Picard ranks of K3
surfaces.
LOCATION:Kemeny 343
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadebcea@math.dartmouth.edu
DTSTART;TZID=America/New_York:20180920T160000
CATEGORIES:Topology Seminar
SUMMARY:Lev Tovstopyat-Nelip: The transverse invariant and braid
dynamics
DESCRIPTION:Let K be a link braided about an open book (B\,p)
supporting a contact manifold (Y\,xi). K and B are naturally
transverse links. We prove that the hat version of the transverse
link invariant defined by Baldwin\, Vela-Vick and Vertesi is
non-zero for the union of K with B. As an application\, we prove
that the transverse invariant of any braid having fractional Dehn
twist coefficient greater than one is non-zero. This generalizes a
theorem of Plamenevskaya about classical braid closures.
LOCATION:Kemeny 201
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadebd38@math.dartmouth.edu
DTSTART;TZID=America/New_York:20180921T153000
CATEGORIES:Math Colloquium
SUMMARY:Tyler Kelly: Mirror Symmetry and Landau-Ginzburg Models
DESCRIPTION:Mirror symmetry is the mathematical study of a duality
from string theory that links different corners of geometry. The
symplectic geometry of one space is encoded in the algebraic
geometry of a new space\, known as its mirror. There have been many
constructions for how to create the mirror for a given space\, but
sometimes they agree and sometimes they do not. We talk about how
they are unified using a structure known as a Landau-Ginzburg model.
A Landau-Ginzburg model is pretty hand-held: it is the data of a
non-compact complex manifold\, a group acting on it and an invariant
holomorphic function. We will discuss how this gadget makes mirror
symmetry clearer and then\, if time permits\, will discuss a new
idea in how to construct a mirror for Landau-Ginzburg models
themselves.
LOCATION:007 Kemeny Hall
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadebd87@math.dartmouth.edu
DTSTART;TZID=America/New_York:20180925T160000
CATEGORIES:Geometry Seminar
SUMMARY:Chen-Yun Lin: An embedding theorem: geometric analysis
behind data analysis
DESCRIPTION:Abstract:\nHigh-dimensional data can be difficult to
analyze. Assume data are\ndistributed on a low-dimensional manifold.
The Vector Diffusion Mapping\n(VDM)\, introduced by Singer-Wu\, is a
non-linear dimension reduction\ntechnique and is shown robust to
noise. It has applications in\ncryo-electron microscopy and image
denoising and has potential\napplication in time-frequency
analysis.\n\nIn this talk\, I will present a theoretical analysis of
the VDM for its\nmathematical foundation. Specifically\, I will
discuss parametrisation of\nthe manifold and an embedding which is
equivalent to the truncated VDM.\nIn the differential geometry
language\, I use eigen-vector fields of the\nconnection Laplacian
operator to construct local coordinate charts that\ndepend only on
geometric properties of the manifold. Next\, I use the\ncoordinate
charts to embed the entire manifold into a
finite-dimensional\nEuclidean space. The proof of the results relies
on solving the elliptic\nsystem and provide estimates for
eigenvector fields and the heat kernel\nand their gradients.\n
LOCATION:307 Kemeny
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadebddb@math.dartmouth.edu
DTSTART;TZID=America/New_York:20180927T160000
CATEGORIES:Topology Seminar
SUMMARY:Samantha Allen: TBA
LOCATION:Kemeny 201
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadebe1c@math.dartmouth.edu
DTSTART;TZID=America/New_York:20180928T160000
CATEGORIES:Math Colloquium
SUMMARY:Bjoern Muetzel: The Jacobian variety of a Riemann surface
with short simple closed geodesics. (Peter Buser\, Eran Makover\,
Bjoern Muetzel and Robert Silhol)
DESCRIPTION:To any compact Riemann surface of genus $g \\geq 2$ one
may assign a principally polarized abelian variety of dimension
$g$\, the Jacobian of the Riemann surface. The Jacobian is a complex
torus and we call a Gram matrix of the lattice of a Jacobian a
period Gram matrix . We give explicit estimates for the entries of
the period Gram matrix with respect to a suitable homology basis\,
if the Riemann surface contains a short simple closed geodesic
$\\gamma$ and study this matrix\, if the geodesic is pinched. If
$\\gamma$ is separating\, then the limit surface can be split into
two surfaces\, each with a cusp. If $\\gamma$ is non-separating\,
then the limit surface has two cusps. We furthermore show how
certain harmonic forms of these limit surfaces extend to harmonic
forms on the compact surfaces which we obtain by adding charts at
the cusp points. As a consequence we obtain that certain
sub-matrices of the period Gram matrices of the pinched surfaces
converge to period Gram matrices of the compactified surfaces.
LOCATION:007 Kemeny Hall
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadebe70@math.dartmouth.edu
DTSTART;TZID=America/New_York:20181004T160000
CATEGORIES:Topology Seminar
SUMMARY:Shelly Harvey: TBA
LOCATION:Kemeny 201
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadebeb2@math.dartmouth.edu
DTSTART;TZID=America/New_York:20181005T153000
CATEGORIES:Math Colloquium
SUMMARY:Shelly Harvey: TBA
LOCATION:Kemeny 007
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadebef2@math.dartmouth.edu
DTSTART;TZID=America/New_York:20181009T153000
DTEND;TZID=America/New_York:20181009T163000
CATEGORIES:Applied and Computational Mathematics Seminar
SUMMARY:Alberto Quattrini Li: TBA
LOCATION:Kemeny 201
URL:http://www.math.dartmouth.edu/~acms
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadebf35@math.dartmouth.edu
DTSTART;TZID=America/New_York:20181009T160000
CATEGORIES:Geometry Seminar
SUMMARY: Peter McGrath: Existence and Uniqueness for Free Boundary
Minimal Surfaces
DESCRIPTION:Let B^3 be the unit ball in R^3 and consider the family
of surfaces contained in B^3 with boundary on the unit sphere S^2.
The critical points of the area functional amongst this class are
called Free Boundary Minimal Surfaces. The latter surfaces are
physically realized by soap films in equilibrium and have been the
subject of intense study. In the 1980s\, it was proved that flat
equatorial disks are the only free boundary minimal surfaces with
the topology of a disk. It is conjectured that a surface called the
critical catenoid is the unique (up to ambient rotations) embedded
free boundary minimal annulus. I will discuss some recent progress
towards resolving this conjecture. I will also discuss some sharp
bounds for the areas of free boundary minimal surfaces in positively
curved geodesic balls which extend works of Fraser-Schoen and
Brendle in the Euclidean setting.
LOCATION:307 Kemeny
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadebf84@math.dartmouth.edu
DTSTART;TZID=America/New_York:20181012T153000
CATEGORIES:Math Colloquium
SUMMARY:Sharon Crook: Data Driven Models in Neuroscience: A
Mathematical Success Story
DESCRIPTION:Building on early work that speculated on the nature of
the electrical properties of neurons\, Hodgkin and Huxley developed
data-driven models for the excitable membrane that still serve as
the basis of many neuroscience models today. A decade later\, Rall
extended these ideas in order to model how the spatial properties of
neurons inform the dynamics of their electrical behavior. In this
talk\, I will discuss how these approaches are being used today to
develop data-driven models that are appropriate for answering
questions about the mechanisms underlying neural computation in the
era of large-scale data. I will examine the issues that arise as
novel technologies bring more and more data to the field\, and I
will introduce some of the tools the community is developing to deal
with these issues.
LOCATION:007 Kemeny Hall
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadebfd4@math.dartmouth.edu
DTSTART;TZID=America/New_York:20181015T160000
DTEND;TZID=America/New_York:20181015T170000
CATEGORIES:Applied and Computational Mathematics Seminar
SUMMARY:Aditya Viswanathan: Phase Retrieval from Local Measurements
DESCRIPTION:Certain imaging applications such as x-ray
crystallography and ptychography require the recovery of a signal
from phaseless (or magnitude-only) measurements - a problem commonly
referred to as Phase Retrieval. This is a challenging (and
non-convex) inverse problem since the phase encapsulates a
significant amount of structure in the underlying signal. Popular
approaches to solving this problem include the method of alternating
projections\, generalized gradient descent techniques\, and convex
relaxations in a higher dimensional ("lifted") space. \n\nIn this
talk\, we will discuss a framework for solving the discrete phase
retrieval problem from deterministic local measurements. We
summarize a recently introduced fast (essentially linear-time) and
robust phase retrieval algorithm based on solving highly structured
(block-circulant) linear systems to infer relative phase
information\, followed by an eigenvector based approach to learning
individual phases from relative phase estimates. Theoretical
recovery guarantees as well as numerical results demonstrating the
method's speed\, accuracy and robustness to measurement errors will
be provided.
LOCATION:Kemeny 201
URL:http://www.math.dartmouth.edu/~acms
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadec02c@math.dartmouth.edu
DTSTART;TZID=America/New_York:20181016T153000
DTEND;TZID=America/New_York:20181016T163000
CATEGORIES:Applied and Computational Mathematics Seminar
SUMMARY:Amro M. Farid: TBA
LOCATION:Kemeny 201
URL:http://www.math.dartmouth.edu/~acms
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadec06f@math.dartmouth.edu
DTSTART;TZID=America/New_York:20181019T153000
CATEGORIES:Math Colloquium
SUMMARY:Jennifer Taback: TBA
LOCATION:Kemeny 007
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadec0b0@math.dartmouth.edu
DTSTART;TZID=America/New_York:20181023T033000
DTEND;TZID=America/New_York:20181023T043000
CATEGORIES:Applied and Computational Mathematics Seminar
SUMMARY:Bo Zhu: TBA
LOCATION:Kemeny 201
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadec0f3@math.dartmouth.edu
DTSTART;TZID=America/New_York:20181025T160000
CATEGORIES:Topology Seminar
SUMMARY:Bulent Tosun: TBA
LOCATION:Kemeny 201
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadec134@math.dartmouth.edu
DTSTART;TZID=America/New_York:20181026T153000
CATEGORIES:Math Colloquium
SUMMARY:Nate Dowlin: TBA
LOCATION:Kemeny 007
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadec174@math.dartmouth.edu
DTSTART;TZID=America/New_York:20181030T143000
DTEND;TZID=America/New_York:20181030T153000
CATEGORIES:Algebra and Number Theory Seminar
SUMMARY:Frank Thorne: TBA
LOCATION:Kemeny 343
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadec1b6@math.dartmouth.edu
DTSTART;TZID=America/New_York:20181030T153000
CATEGORIES:Applied and Computational Mathematics Seminar
SUMMARY:Douglas Cochran: TBA
LOCATION:Kemeny 201
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadec1f6@math.dartmouth.edu
DTSTART;TZID=America/New_York:20181030T160000
DTEND;TZID=America/New_York:20181030T170000
CATEGORIES:Algebra and Number Theory Seminar
SUMMARY:Robert Lemke Oliver: TBA
LOCATION:Kemeny 343
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadec238@math.dartmouth.edu
DTSTART;TZID=America/New_York:20181103T160000
CATEGORIES:Math Colloquium
SUMMARY:Peter Mucha: TBA
LOCATION:Kemeny 007
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadec278@math.dartmouth.edu
DTSTART;TZID=America/New_York:20181109T153000
CATEGORIES:Math Colloquium
SUMMARY:Ken Golden: Celebration of Science at Dartmouth
LOCATION:Kemeny 007
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadec2b9@math.dartmouth.edu
DTSTART;TZID=America/New_York:20190103T160000
CATEGORIES:Math Colloquium
SUMMARY:Lassina Dembele: TBA
LOCATION:Haldeman 41
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadec2fa@math.dartmouth.edu
DTSTART;TZID=America/New_York:20190111T153000
CATEGORIES:Math Colloquium
SUMMARY:Christopher Jones: TBA
LOCATION:Kemeny 007
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadec33a@math.dartmouth.edu
DTSTART;TZID=America/New_York:20190228T143000
CATEGORIES:Topology Seminar
SUMMARY:Joshua Sussan: TBA
LOCATION:Kemeny 201
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadec37b@math.dartmouth.edu
DTSTART;TZID=America/New_York:20190301T153000
CATEGORIES:Math Colloquium
SUMMARY:Penny Haxell: TBA
LOCATION:Kemeny 007
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadec3bb@math.dartmouth.edu
DTSTART;TZID=America/New_York:20190405T153000
CATEGORIES:Math Colloquium
SUMMARY:Robert Low: Space-time topology: choices and consequences
DESCRIPTION:I will review some of the possible choices of topology
on a Lorentz manifold and their well-known properties. Following
this\, I will take a more detailed look at some of the advantages
and disadvantages of the main choices. Finally (depending on
progress over the next few months) I may spend some time examining
the special case of 2 dimensional Minkowski space.
LOCATION:007 Kemeny Hall
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadec404@math.dartmouth.edu
DTSTART;TZID=America/New_York:20190405T170000
CATEGORIES:Topology Seminar
SUMMARY:Robert Low: Causal structure and spaces of null geodesics
DESCRIPTION:I will review Lorentz manifolds as a model of
space-time\, and how the important notion of causal structure arises
in this context. Then\, observing the fundamental nature of null
geodesics to this structure\, I will describe the space of null
geodesics and the natural topological and geometric structures it
carries. Finally\, I will consider how aspects of the causal
structure of the original space-time is encoded in this space of
null geodesics\, culminating in the notion of Legendrian linking of
those submanifolds in the space of null geodesics representing
points of the space-time.
LOCATION:Kemeny 201
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadec44f@math.dartmouth.edu
DTSTART;TZID=America/New_York:20190411T163000
CATEGORIES:Topology Seminar
SUMMARY:Alexander Dranishnikov: TBA
LOCATION:Kemeny 201
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadec490@math.dartmouth.edu
DTSTART;TZID=America/New_York:20190412T153000
CATEGORIES:Math Colloquium
SUMMARY:Alexander Dranishnikov: TBA
LOCATION:Kemeny 007
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20180919T031701Z
UID:20180918T2317015ba1bfadec4d0@math.dartmouth.edu
DTSTART;TZID=America/New_York:20190502T160000
CATEGORIES:Math Colloquium
SUMMARY:Dick Canary: TBA
LOCATION:Haldeman 41
END:VEVENT
END:VCALENDAR