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X-WR-CALNAME:Mathematics Department
BEGIN:VEVENT
DTSTAMP:20190619T130201Z
UID:20190619T0902015d0a3249290aa@math.dartmouth.edu
DTSTART;TZID=America/New_York:20190521T141500
CATEGORIES:Combinatorics Seminar
SUMMARY:Alejandro Morales: Determinant formulas for counting linear
extensions of tree posets
DESCRIPTION:The number of linear extensions of a poset set is a
fundamental measure of the complexity of a poset that is of interest
in algebraic combinatorics. Brightwell and Winkler showed that
computing this number is hard (#P-complete) but there still are
certain families of posets with nice formulas for their number of
linear extensions. These include product formulas for posets coming
from Young diagrams and rooted trees and determinant formulas for
skew Young diagrams and the number of permutations with given
descent sets. We study a family of posets coming from trees (not
necessarily rooted) that have a determinantal formulas for their
number of linear extensions.\n\nThis is joint work with Al Garver\,
Jacob Matherne and Stefan Grosser.
LOCATION:TBA
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20190619T130201Z
UID:20190619T0902015d0a324929198@math.dartmouth.edu
DTSTART;TZID=America/New_York:20190523T110000
DTEND;TZID=America/New_York:20190523T120000
CATEGORIES:Functional Analysis Seminar
SUMMARY:Peter Woit: The quantum Weil algebra and representation
theory
DESCRIPTION:Representations of a Lie algebra are usually studied
using the universal enveloping algebra. In many cases one can
instead work with a larger structure called the quantum Weil
algebra\, which also involves a Clifford algebra and Dirac operator.
I'll explain some ideas relating this algebra and the construction
of Lie algebra representations in terms of spinors and the Dirac
operator.
LOCATION:307 Kemeny Hall
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BEGIN:VEVENT
DTSTAMP:20190619T130201Z
UID:20190619T0902015d0a324929245@math.dartmouth.edu
DTSTART;TZID=America/New_York:20190523T143000
DTEND;TZID=America/New_York:20190523T153000
CATEGORIES:Algebra and Number Theory Seminar
SUMMARY:Brandon Williams: Hilbert modular forms and Borcherds
products
DESCRIPTION:Borcherds products are modular forms on orthogonal
groups with known divisors. I will talk about an application of
these products to computing graded rings of Hilbert modular forms.
LOCATION:Kemeny 343
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20190619T130201Z
UID:20190619T0902015d0a3249292e3@math.dartmouth.edu
DTSTART;TZID=America/New_York:20190523T143000
CATEGORIES:Topology Seminar
SUMMARY:Cornelia Van Cott: Nonorientable three- and four-genus of
torus knots
DESCRIPTION:We will discuss the nonorientable surfaces that torus
knots bound. We use a surface construction introduced by Josh Batson
together with tools from knot Floer homology to compute the
nonorientable four-genus of infinite families of torus knots.
Comparing this surface construction with the surfaces realizing
torus knots' non-orientable three-genus\, we show that the
difference between nonorientable three- and four-genus can be
arbitrarily large. This contrasts with the analogous situation in
the orientable world. Kronheimer and Mrowka proved in 1993 that both
the orientable three-genus and the orientable four-genus for T(p\,q)
are equal to (p-1)(q-1)/2. This is joint work with Stanislav Jabuka.
LOCATION:201 Kemeny
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20190619T130201Z
UID:20190619T0902015d0a324929396@math.dartmouth.edu
DTSTART;TZID=America/New_York:20190523T163000
CATEGORIES:Math Colloquium
SUMMARY:Peter Woit: Quantization and the Dirac operator
DESCRIPTION:Lie algebras appear in many guises in fundamental
physics\, with the theory of their representations intimately
related to quantum mechanics. In recent years it has become clear
that the Dirac operator\, known to play a central role in the
quantum description of elementary particles\, plays an equally
central role in the general theory of representations of Lie
algebras. I'll explain this circle of ideas\, and work out some
examples.
LOCATION:007 Kemeny Hall
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20190619T130201Z
UID:20190619T0902015d0a324929443@math.dartmouth.edu
DTSTART;TZID=America/New_York:20190524T153000
CATEGORIES:Math Colloquium
SUMMARY:Semyon Dyatlov: What is quantum chaos?
DESCRIPTION:Where do eigenfunctions of the Laplacian concentrate as
eigenvalues go to infinity? Do they equidistribute or do they
concentrate in an uneven way? It turns out that the answer depends
on the nature of the geodesic flow. I will discuss various results
in the case when the flow is chaotic: the Quantum Ergodicity theorem
of Shnirelman\, Zelditch\, and Colin de Verdi\\`ere\, the Quantum
Unique Ergodicity conjecture of Rudnick--Sarnak\, the progress on
it by Lindenstrauss and Soundararajan\, and the entropy bounds of
Anantharaman--Nonnenmacher. I will conclude with recent lower bounds
on the mass of eigenfunctions obtained with Jin and Nonnenmacher.
They rely on a new tool called "fractal uncertainty principle"
developed in the works with Bourgain and Zahl.
LOCATION:007 Kemeny Hall
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20190619T130201Z
UID:20190619T0902015d0a3249294ed@math.dartmouth.edu
DTSTART;TZID=America/New_York:20190528T140000
DTEND;TZID=America/New_York:20190528T150000
CATEGORIES:Applied and Computational Mathematics Seminar
SUMMARY:Victor Churchill: (High Order) Total Variation Bayesian
Learning via Synthesis
DESCRIPTION:Deterministic inverse problems in signal and image
processing with a transform sparsity prior are typically posed in
the analysis formulation. I will begin by developing an equivalent
synthesis approach for the widely used (high order) total variation
(HOTV) operator. This is significant as it allows us to consider
more complex problems as sparse signal recovery. While this likely
has other important consequences\, in this talk I will form a sparse
Bayesian learning (SBL) algorithm for inverse problems with a HOTV
sparsity prior. For sparse signal recovery\, SBL often produces a
more accurate estimate than the standard analysis-based approaches.
While it has the advantage of providing a posterior distribution
rather than just a maximum a posteriori Bayesian estimate\, its
computational cost and the fact that it requires direct or synthesis
sparsity have limited its application in imaging. Hence in this
technique\, we employ SBL only to accurately detect the transform
sparsity representation\, and then we transform back to the image
domain using the new HOTV synthesis operator. I will also discuss
the acceleration of the method for imaging using a line-by-line
approach. If time allows\, I may briefly discuss the potential use
of HOTV synthesis operators in other Bayesian methods.
LOCATION:Haldeman 252
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20190619T130201Z
UID:20190619T0902015d0a3249295ab@math.dartmouth.edu
DTSTART;TZID=America/New_York:20190528T153000
CATEGORIES:Geometry Seminar
SUMMARY:Melkana Brakalova: p-integrable Teichmuller spaces from the
quasi-conformal mappings point of view
DESCRIPTION:There are different approaches to investigating
properties of the universal Teichmüller space $\\mathcal T$ and its
many subspaces. We consider $\\mathcal T$ to be the set of
equivalent classes of quasisymmetric automorphisms of the real line
or of the unit circle. We are interested in the $p$-integrable
subspaces $\\mathcal T_p\,\\ p>0\,$ of $\\mathcal T$\, which we
define as the equivalent classes of quasisymmetric automorphisms
that admit a q.c. extension (to the upper half-plane or the unit
disk\, resp.) with $p$-integrable complex dilatation w.r.t. the
Poincare metric (finite hyperbolic $L^p$ norm). We show that such
spaces belong to the little Teichmüller space and that they are
continuously differentiable for $ 0 < p \\leq 1 $ using local
properties of quasiconformal maps. We discuss the length space
property of the $T^p$ spaces and some open questions. This is work
in progress joint with V. Alberge.
LOCATION:Kemeny 307
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20190619T130201Z
UID:20190619T0902015d0a324929663@math.dartmouth.edu
DTSTART;TZID=America/New_York:20190528T163000
CATEGORIES:Kemeny Lecture
SUMMARY:Ingrid Daubechies: Surfing with Wavelets - Undergraduate
talk
DESCRIPTION:Surfing with Wavelets\nThis talk gives an overview of
wavelets: what they are\, how they work\, why they are useful for
image analysis and image compression. Then it will go on to discuss
how they have been used recently for the study of paintings by e.g.
Van Gogh\, Goossen van der Weyden\, Gauguin and Giotto.\n\n \n\nFYI
(this particular talk can be given without a single mathematical
formula\, or at various levels of mathematical complexity: for
undergrads\, for graduate students\, or very technical. It is also
possible to give the wide-audience talk first\, and then revisit
it\, pausing at various places to digress and explain what is going
on mathematically.)
LOCATION:Haldeman 041
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DTSTAMP:20190619T130201Z
UID:20190619T0902015d0a32492970b@math.dartmouth.edu
DTSTART;TZID=America/New_York:20190528T190000
CATEGORIES:Kemeny Lecture
SUMMARY:Ingrid Daubechies: Mathematicians Helping Art Conservators
and Art Historians - Public lecture
DESCRIPTION:This lecture will review several instances where
mathematics have helped art historians and art conservators in
studying and understanding art works in the last decade or so. Some
of them led (and are still leading) to interesting new challenges in
signal and image analysis. In other applications\, we can virtually
rejuvenate art works\, bringing a different understanding and
experience of the art to museum visitors as well as to experts.
LOCATION:Life Sciences Center 100\, Arvo J. Oopik '78 Auditorium
END:VEVENT
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DTSTAMP:20190619T130201Z
UID:20190619T0902015d0a3249297c1@math.dartmouth.edu
DTSTART;TZID=America/New_York:20190529T113000
CATEGORIES:Math Colloquium
SUMMARY:Ingrid Daubechies: Lovely Bones: a meeting of mathematical
and biological minds
DESCRIPTION:The talk will present mathematical explorations
motivated by the need of biological morphologists to compare
different phenotypical structures. At present\, scientists using
physical traits to study evolutionary relationships among living and
extinct animals analyze data extracted from carefully defined
anatomical correspondence points (landmarks). Identifying and
recording these landmarks is time consuming and can be done
accurately only by trained morphologists. This necessity renders
these studies inaccessible to non-morphologists and causes phenomics
to lag behind genomics in elucidating evolutionary
patterns.\n\nUnlike other algorithms presented for morphological
correspondences\, the approach presented in the talk does not
require any preliminary marking of special features or landmarks by
the user. It also differs from other seminal work in computational
geometry in that the algorithms are polynomial in nature and thus
faster\, making pairwise comparisons feasible for significantly
larger numbers of digitized surfaces.\n\nThis approach has already
been used by biologists to obtain new results.\nAnd there are many
further avenues to be explored!
LOCATION:Haldeman 041
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20190619T130201Z
UID:20190619T0902015d0a3249298a6@math.dartmouth.edu
DTSTART;TZID=America/New_York:20190610T150000
DTEND;TZID=America/New_York:20190610T170000
CATEGORIES:Special Event
SUMMARY:Mathematics Alumni Open House
DESCRIPTION:Academic Open House for classes 1959\, 1954\, and 1969.
LOCATION:Kemeny 300
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20190619T130201Z
UID:20190619T0902015d0a324929945@math.dartmouth.edu
DTSTART;TZID=America/New_York:20190614T150000
DTEND;TZID=America/New_York:20190614T170000
CATEGORIES:Special Event
SUMMARY:Mathematics Alumni Open House
DESCRIPTION:Academic Open House for classes 1973\, 1974\, 1975\,
1989\, 1994\, 2003\, 2004\, 2005\, and 2014
LOCATION:Kemeny 300
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20190619T130201Z
UID:20190619T0902015d0a3249299f0@math.dartmouth.edu
DTSTART;TZID=America/New_York:20190722T130000
DTEND;TZID=America/New_York:20190722T160000
CATEGORIES:Special Event
SUMMARY:Math Camp 1
LOCATION:Kemeny Hall
URL:http://www.math.dartmouth.edu/activities/exploring-mathematics/
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20190619T130201Z
UID:20190619T0902015d0a324929a86@math.dartmouth.edu
DTSTART;TZID=America/New_York:20190805T130000
DTEND;TZID=America/New_York:20190805T160000
CATEGORIES:Special Event
SUMMARY:Math Camp 2
LOCATION:Kemeny Hall
URL:http://www.math.dartmouth.edu/activities/exploring-mathematics/
END:VEVENT
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