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Texas A&M University

Events for 10/02/2020 from all calendars

Mathematical Physics and Harmonic Analysis Seminar

iCal  iCal

Time: 1:50PM - 2:50PM

Location: Zoom

Speaker: Rodrigo Matos, TAMU

Title: Dynamical Contrast on Highly Correlated Anderson-type models

Abstract: We present examples of random Schödinger operators obtained in a similar fashion but exhibiting distinct transport properties. The models are constructed by connecting, in different ways, infinitely many copies of the one dimensional Anderson model. Spectral aspects of the models will also be presented. In particular, we obtain a physically motivated example of a random operator with purely absolutely continuous spectrum where the transient and recurrent components coexist. This can be interpreted as a sharp phase transition within the absolutely continuous spectrum. Time allowing, I will discuss some tools related to harmonic analysis, including a version of Boole's equality which, to the best of our knowledge, is new. Based on joint work with Rajinder Mavi and Jeffrey Schenker.

Algebra and Combinatorics Seminar

iCal  iCal

Time: 3:00PM - 4:00PM

Location: Zoom

Speaker: Bridget Tenner, DePaul University

Title: Odd diagram classes of permutations

Abstract: Recently, Brenti and Carnevale introduced an odd analogue of the classical permutation diagram. This gives rise to odd analogues of other permutation aspects such as length and inversions. Unlike in the classical setting, multiple permutations might have the same odd diagram. This prompts the study of "odd diagram classes": sets of permutations having the same odd diagram. We will discuss the rich combinatorial structure of these classes, including connections to pattern avoiding permutations and the Bruhat order. This is joint work with Francesco Brenti and Angela Carnevale.

Open Teaching with Technology Forum

iCal  iCal

Time: 3:30PM - 5:00PM

Location: Zoom

Speaker: Vanessa Coffelt

Description: Join Zoom Meeting: Meeting ID: 931 4271 8312

Geometry Seminar

iCal  iCal

Time: 4:00PM - 5:00PM

Location: zoom

Speaker: David, Sykes, TAMU

Title: Local equivalence problems for 2-nondegenerate, hypersurface-type CR geometry studied via dynamical Legendrian contact structures.

Abstract: The local differential geometry of Levi-nondegenerate CR structures is well understood due in large part to classical results of Cartan, Tanaka, Chern, and Moser, and yet comparatively little is known about other CR structures. There is a natural association between 2-nondegenerate, hypersurface-type CR structures – which are the main focus of this talk – and dynamical Legendrian contact structures, and, moreover, there is a broad class of these CR structures that can be uniquely recovered from their associated dynamical Legendrian contact structure. For these recoverable structures, we construct canonical absolute parallelisms on fiber bundles defined over a manifold with the given CR structure. The construction can be applied to discern local equivalence between CR structures. Other applications that will be discussed include upper bounds for the dimension of a CR manifold’s symmetry group and a characterization of local invariants of certain homogeneous CR manifolds. The latter application, coupled with results by Curtis Porter and Igor Zelenko, enables us to classify the local geometry of homogeneous, 2-nondegenerate, hypersurface-type CR manifolds in low dimensions.