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VERSION:2.0
METHOD:PUBLISH
PRODID:-//Mathematics Department//NONSGML mathical.php//EN
X-WR-CALNAME:Mathematics Department
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e05c9@math.dartmouth.edu
DTSTART;TZID=America/New_York:20191112T110000
CATEGORIES:Combinatorics Seminar
SUMMARY:Duncan Levear: A bijection for the faces of the Shi
arrangement
DESCRIPTION:A collection of hyperplanes induces a cellular structure
on n-dimensional space. We consider the combinatorial question of
counting the number of cells of each dimension. There is a rich
history behind counting the highest-dimensional cells (called the
regions)\, but the lower-dimensional cells (called the faces) have
received less attention. In this talk\, I will survey some of the
combinatorics of hyperplane arrangements\, and describe recent
work\, which places the faces of the Shi arrangement in bijective
correspondence with a set of decorated binary trees. Furthermore\,
I will show that this set of binary trees can be converted to a set
of Cayley trees\, or further to simple integer sequences known as
Prufer Codes. This bijection is a generalization of one for regions
defined by Bernardi in 2015.
LOCATION:Kemeny 120
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e0707@math.dartmouth.edu
DTSTART;TZID=America/New_York:20191112T140000
CATEGORIES:Applied and Computational Mathematics Seminar
SUMMARY:Sean Carney: Title: Numerical multiscale methods and
effective boundary conditions
DESCRIPTION:Abstract: Numerical homogenization refers to the
computational extraction of the effective\, "macroscopic"\, or
large-scale behavior of a complex dynamical system at a reduced cost
to resolving the full dynamics at all levels of detail. The no-slip
boundary condition (BC) for viscous fluid flow over a solid surface
can introduce asymptotically small scales that pose severe
challenges for simulation\; in this case it can be preferable to
replace the no-slip condition with a homogenized BC. This talk
discusses numerical techniques for generating effective BC\, or wall
laws\, for laminar flows over rough boundaries\, as well as
turbulent boundary layer flows for constant favorable\, zero\, or
adverse $\\nabla p$. Guided by rigorous mathematics in the former
case and recent empirical advances in the latter\, numerical
strategies are presented to overcome the high computational cost of
resolving the full near wall dynamics. In both settings\, the main
idea consists of running high resolution simulations in a relatively
small domain localized to the boundary. Numerical examples presented
throughout validate the modeling approach.
LOCATION:Haldeman 252 (The Neukom Conference Room)
URL:https://math.dartmouth.edu/~acms/
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e081c@math.dartmouth.edu
DTSTART;TZID=America/New_York:20191114T140000
CATEGORIES:Applied and Computational Mathematics Seminar
SUMMARY:Paul Constantine: Title: Active subspaces: Emerging ideas
for parameter reduction in computational science and engineering
DESCRIPTION:Abstract: Scientists and engineers use computer
simulations to study relationships between a physical model's input
parameters and its output predictions. However\, thorough parameter
studies---e.g.\, constructing response surfaces\, optimizing\, or
averaging---are challenging\, if not impossible\, when the
simulation is expensive and the model has several inputs. To enable
parameter studies in these instances\, the engineer may attempt to
reduce the dimension of the model's input parameter space using
techniques such as sensitivity analysis or variable screening to
identify unimportant variables that can be fixed for model analysis.
Generalizing classical coordinate-based reduction\, there are
several emerging subspace-based parameter reduction tools\, such as
active subspaces and sufficient dimension reduction\, that identify
important directions in the input parameter space with respect to a
particular model output. I will motivate and provide an overview of
subspace-based parameter reduction techniques and discuss strategies
for exploiting such low-dimensional structures---including analysis
and computation---to enable otherwise infeasible parameter studies.
For more information\, see activesubspaces.org.
LOCATION:Haldeman 252 (Neukom Conference Room)
URL:https://math.dartmouth.edu/~acms/
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e0935@math.dartmouth.edu
DTSTART;TZID=America/New_York:20191114T140000
CATEGORIES:Topology Seminar
SUMMARY:Siddhi Krishna: Taut Foliations\, Positive 3-Braids\, and
the L-Space Conjecture
DESCRIPTION:The L-Space Conjecture is taking the low-dimensional
topology community by storm. It aims to relate seemingly distinct
Floer homological\, algebraic\, and geometric properties of a closed
3-manifold Y. In particular\, it predicts a 3-manifold Y isn't
"simple" from the perspective of Heegaard-Floer homology if and only
if Y admits a taut foliation. The reverse implication was proved by
Ozsváth and Szabó. In this talk\, we'll present a new theorem
supporting the forward implication. Namely\, we'll build taut
foliations for manifolds obtained by surgery on positive 3-braid
closures. Our theorem provides the first construction of taut
foliations for every non-L-space obtained by surgery along an
infinite family of hyperbolic L-space knots. As an example\, we'll
construct taut foliations in every non-L-space obtained by surgery
along the P(-2\,3\,7) pretzel knot. No background in Floer homology
or foliation theories will be assumed.\n
LOCATION:201 Kemeny
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e0a36@math.dartmouth.edu
DTSTART;TZID=America/New_York:20191119T110000
CATEGORIES:Combinatorics Seminar
SUMMARY:Alexander Wilson: Transition matrices for symmetric
functions and combinatorial interpretations
DESCRIPTION: will introduce five bases for the space of symmetric
functions as well as define an inner product and involution on the
space. Using these tools we can write the transition matrices
between each of these bases in terms of the Kostka matrix\, whose
coefficients are the number of semi-standard young tableaux with a
given shape and content. Finally\, I will discuss some properties of
the matrices and give combinatorial interpretations of some of the
identities that we obtained through the linear algebra.
LOCATION:Kemeny 120
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e0b20@math.dartmouth.edu
DTSTART;TZID=America/New_York:20191119T140000
CATEGORIES:Applied and Computational Mathematics Seminar
SUMMARY:Chris Rackauckas: Title: Neural Differential Equations as a
Basis for Scientific Machine Learning
DESCRIPTION:Abstract: Scientific Machine Learning (SciML) is an
emerging discipline which merges the mechanistic models of science
and engineering with non-mechanistic machine learning models to
solve problems which were previously intractable. Recent results
have showcased how methods like Physics Informed Neural Networks
(PINNs) can be utilized as a data-efficient learning method\,
embedding the structure of physical laws as a prior into a learnable
structures so that small data and neural networks can sufficiently
predict phenomena. Additionally\, deep learning embedded within
backwards stochastic differential equations has been shown to be an
effective tool for solving high-dimensional partial differential
equations\, like the Hamilton-Jacobian-Bellman equation with 1000
dimensions. In this talk we will introduce the audience to these
methods and show how these diverse methods are all instantiations of
a neural differential equation\, a differential equation where all
or part of the equation is described by a latent neural network.
Once this is realized\, we will show how a computational tool\,
DiffEqFlux.jl\, is being optimized to allow for efficient training
of a wide variety of neural differential equations\, explaining how
the performance properties of these equation differ from more
traditional uses of differential equations and some of the early
results of optimizing for this domain. The audience will leave
knowing how neural differential equations and DiffEqFlux.jl may be a
vital part of next-generation scientific tooling.
LOCATION:Haldeman 252 (Neukom Conference Room)
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e0c3d@math.dartmouth.edu
DTSTART;TZID=America/New_York:20191119T160000
CATEGORIES:Geometry Seminar
SUMMARY:Peter Buser: Viewing the distribution of simple closed
geodesics on a Riemann surface
DESCRIPTION:By a result of Joan Birman and Caroline Series the union
set $BS$ of all simple closed geodesics on a compact hyperbolic
surface $R$ is nowhere dense. So then\, how dense are they? In joint
work with Hugo Parlier we have estimated the sizes of regions on $R$
into which the simple closed geodesics do not enter. To see how
accurate the bounds are we aim to visualise $BS$ by computer. In the
talk we discuss an algorithm for the generation of the simple closed
geodesics on $R$ and an idea for an algorithm that yields
graphically representable sets $BS'$ that contain $BS$ and have
small Hausdorff distance to it.
LOCATION:Kemeny 307
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e0d51@math.dartmouth.edu
DTSTART;TZID=America/New_York:20200107T143000
DTEND;TZID=America/New_York:20200107T153000
CATEGORIES:Algebra and Number Theory Seminar
SUMMARY:Alicia Lamarche: TBA
LOCATION:343 Kemeny Hall
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e0e29@math.dartmouth.edu
DTSTART;TZID=America/New_York:20200114T140000
CATEGORIES:Applied and Computational Mathematics Seminar
SUMMARY:Akshay K. Mehra: Title: TBA
LOCATION:Haldeman 252 (Neukom Conference Room)
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e0ef9@math.dartmouth.edu
DTSTART;TZID=America/New_York:20200123T153000
CATEGORIES:Math Colloquium
SUMMARY:June Huh: TBA
LOCATION:004 Kemeny
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e0fcd@math.dartmouth.edu
DTSTART;TZID=America/New_York:20200128T140000
CATEGORIES:Applied and Computational Mathematics Seminar
SUMMARY:Min Hyung Cho: title: TBA
LOCATION:Haldeman Center 252 (Neukom Conference Room)
URL:https://math.dartmouth.edu/~acms/
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e109b@math.dartmouth.edu
DTSTART;TZID=America/New_York:20200128T143000
DTEND;TZID=America/New_York:20200128T153000
CATEGORIES:Algebra and Number Theory Seminar
SUMMARY:Taylor Dupuy: TBA
LOCATION:343 Kemeny Hall
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e1166@math.dartmouth.edu
DTSTART;TZID=America/New_York:20200204T140000
CATEGORIES:Applied and Computational Mathematics Seminar
SUMMARY:Wojciech Jarosz: Title: TBA
LOCATION:Haldeman 252 (Neukom Conference Room)
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e1235@math.dartmouth.edu
DTSTART;TZID=America/New_York:20200206T153000
CATEGORIES:Math Colloquium
SUMMARY:Carl Mautner: TBA
LOCATION:004 Kemeny
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e1306@math.dartmouth.edu
DTSTART;TZID=America/New_York:20200211T140000
CATEGORIES:Applied and Computational Mathematics Seminar
SUMMARY:Xingru Chen: Title: TBA
LOCATION:Haldeman 252 (Neukom Conference Room)
URL:http://www.math.dartmouth.edu/~acms/
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e13d4@math.dartmouth.edu
DTSTART;TZID=America/New_York:20200218T140000
CATEGORIES:Applied and Computational Mathematics Seminar
SUMMARY:Lizzie Tripp: Title: TBA
LOCATION:Haldeman 252 (Neukom Conference Room)
URL:http://www.math.dartmouth.edu/~acms/
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e14b4@math.dartmouth.edu
DTSTART;TZID=America/New_York:20200225T140000
CATEGORIES:Applied and Computational Mathematics Seminar
SUMMARY:Jim Lambers: Title: TBA
LOCATION:Haldeman 252 (Neukom Conference Room)
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e1583@math.dartmouth.edu
DTSTART;TZID=America/New_York:20200227T153000
CATEGORIES:Math Colloquium
SUMMARY:Ben Adcock: TBA
LOCATION:004 Kemeny
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e1650@math.dartmouth.edu
DTSTART;TZID=America/New_York:20200303T143000
DTEND;TZID=America/New_York:20200303T153000
CATEGORIES:Algebra and Number Theory Seminar
SUMMARY:Julian Rosen: TBA
LOCATION:343 Kemeny Hall
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e171a@math.dartmouth.edu
DTSTART;TZID=America/New_York:20200403T160000
DTEND;TZID=America/New_York:20200403T170000
CATEGORIES:Algebra and Number Theory Seminar
SUMMARY:Mark de Cataldo: TBA
LOCATION:343 Kemeny Hall
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e17e3@math.dartmouth.edu
DTSTART;TZID=America/New_York:20200407T140000
CATEGORIES:Applied and Computational Mathematics Seminar
SUMMARY:Matt Jones: Title: TBA
LOCATION:Haldeman 252 (Neukom Conference Room)
URL:http://www.math.dartmouth.edu/~acms
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e18b5@math.dartmouth.edu
DTSTART;TZID=America/New_York:20200414T140000
CATEGORIES:Applied and Computational Mathematics Seminar
SUMMARY:Laura Petto: Title: TBA
LOCATION:Haldeman 252 (Neukom Conference Room)
URL:http://www.math.dartmouth.edu/~acms/
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e1986@math.dartmouth.edu
DTSTART;TZID=America/New_York:20200416T153000
CATEGORIES:Math Colloquium
SUMMARY:Tony Guttmann: Recent developments in self-avoiding walks.
DESCRIPTION:The canonical problem of calculating the properties of
self-avoiding walks (SAWs) has been studied for nearly 80 years.
Remarkably little has been proved. In this talk I will give a brief
introduction to SAWs\, review what is known\, and what is widely
believed to be true\, but has not been proved. Then I will outline
three recent calculations:\n(i) New scaling laws. (ii) The SAW at
the theta point. (iii) Attempts to prove the existence of the
critical exponent for two-dimensional SAWs. Minimal prior knowledge
is assumed.
LOCATION:004 Kemeny Hall
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e1a71@math.dartmouth.edu
DTSTART;TZID=America/New_York:20200421T140000
CATEGORIES:Applied and Computational Mathematics Seminar
SUMMARY:Yitong Huang: Title: TBA
LOCATION:Haldeman 252 (Neukom Conference Room)
URL:http://www.math.dartmouth.edu/~acms/
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e1b58@math.dartmouth.edu
DTSTART;TZID=America/New_York:20200505T143000
DTEND;TZID=America/New_York:20200505T153000
CATEGORIES:Algebra and Number Theory Seminar
SUMMARY:Owen Biesel: TBA
LOCATION:Kemeny 343
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e1c24@math.dartmouth.edu
DTSTART;TZID=America/New_York:20200518T180000
CATEGORIES:Kemeny Lecture
SUMMARY:Richard Schwarz: TBA
LOCATION:Kemeny 008
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e1cf9@math.dartmouth.edu
DTSTART;TZID=America/New_York:20200519T160000
CATEGORIES:Kemeny Lecture
SUMMARY:Richard Schwarz: TBA
LOCATION:Haldeman 041
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e1d96@math.dartmouth.edu
DTSTART;TZID=America/New_York:20200520T160000
CATEGORIES:Kemeny Lecture
SUMMARY:Richard Schwarz: TBA
LOCATION:Haldeman 041
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e1dfa@math.dartmouth.edu
DTSTART;TZID=America/New_York:20200928T180000
CATEGORIES:Kemeny Lecture
SUMMARY:Nigel Higson: TBA
LOCATION:Kemeny 008
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e1e61@math.dartmouth.edu
DTSTART;TZID=America/New_York:20200929T160000
CATEGORIES:Kemeny Lecture
SUMMARY:Nigel Higson: TBA
LOCATION:Haldeman 041
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20191210T133201Z
UID:20191210T0832015def9e51e1ec7@math.dartmouth.edu
DTSTART;TZID=America/New_York:20200930T160000
CATEGORIES:Kemeny Lecture
SUMMARY:Nigel Higson: TBA
LOCATION:Haldeman 041
END:VEVENT
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