Title: Contact structures and the mapping class group of lens spaces Abstract: One important problem in contact topology is to classify contact structures on a given manifold. Around 20 years ago, Giroux and Honda classified contact structures on lens spaces. A natural question to ask after that is how the transformations on lens spaces interact […]
Title: Lonely Runners and My Favorite Polyhedron Speaker: Matthias Beck, Department of Mathematics, San Francisco State University Abstract: We study the Lonely Runner Conjecture, conceived by Wills in the 1960's, and originally phrased in terms of Diophantine approximation: Given positive integers n_1, n_2, ..., n_k, there exists a positive real number t such that for all […]
Title: On the Composition of Classical Mechanical Systems Abstract: Compositionality is a basic principle for understanding the physical world. The underlying idea is to study a system by studying the ways in which the components of the system compose to form the system. Category theory is an area in mathematics that is particularly well-suited for […]
True Grit: Writing the History of Women at Yerkes Observatory, 1895–1950 Abstract: Women at Yerkes Observatory earned advanced degrees, conducted their own research, collaborated on projects with peers of both sexes, and authored publications in their own names in the first half of the Twentieth Century. Yet Alice Hall Farnsworth, Mary Murray Hopkins, Harriet McWilliams […]
The Ehrhart polynomial of a lattice polytope P counts the number of integer points in the nth integral dilate of P. The f^* -vector of P, introduced by Felix Breuer in 2012, is the vector of coefficients of the Ehrhart polynomial with respect to the binomial coefficient basis . Similarly to h and h^* -vectors, […]
On November 14th, Tuesday from 3-4pm in Fletcher 110, Geometry and Topology Seminar invites students and faculty to a course preview session devoted to a discussion and presentations about upcoming Spring 2024 courses in geometry, topology and/or with applications in geometry and topology to help students make their enrollment choices. We will have some refreshments […]
Title: Adinkra Heights and Color-Splitting Rainbows Speaker: Ursula Whitcher, American Mathematical Society Abstract: Adinkras are decorated graphs that encapsulate information about conjectural relationships between fundamental particles in physics. If we color the edges of an Adinkra with a rainbow of shades in a specific order, we obtain a special curve that we can study usingalgebraic […]
The Effros-Shen algebra corresponding to an irrational number $\theta$ can be described by an inductive sequence of direct sums of matrix algebras, where the continued fraction expansion of $\theta$ encodes the dimensions of the summands, and how the matrix algebras at the nth level fit into the summands at the (n+1)th level. In recent work, […]
Inventing the ‘Islamic Golden Age’: Orientalism and the History of Mathematics Abstract: TBA
The Cox ring of a projective variety is the ring of all its meromorphic functions, together with a grading of geometric origin. Determining whether this ring is finitely generated is a challenging task, even for simple examples. In this talk, we will discuss our efforts to tackle this problem for a specific class of varieties, […]
A simple question about chicken nuggets connects everything from analysis and combinatorics to probability theory and computer-aided design. With tools from complex, harmonic, and functional analysis, probability theory, algebraic combinatorics, and spline theory, we answer many asymptotic questions about factorization lengths in numerical semigroups. Our results yield uncannily accurate predictions, along with unexpected results about […]
Title: Skein Theory of Affine ADE Subfactor Planar Algebras Abstract: Subfactor planar algebras first were constructed by Vaughan Jones as a diagrammatic axiomatization of the standard invariant of a subfactor. These planar algebras also encode two other invariants of the subfactors: the index and the principal graph. The Kuperberg Program asks to find all diagrammatic […]
