SEMINARS, HARVARD-MIT COMBINATORICS
April 24, 2024 4:15 pmLet (W,S) be a Coxeter system, and write S={s_i : i is in I}, where I is a finite index set. Consider a nonempty finite convex subset L of W....
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SEMINARS, HARVARD-MIT COMBINATORICS
April 19, 2024 3:00 pmMarkov chains provide a natural approach to sample from various distributions on the independent sets of a graph. For the uniform distribution on independent sets of a given size $k$...
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SEMINARS, HARVARD-MIT COMBINATORICS
April 18, 2024 4:00 pm**Special Time and Location** The degeneracy of a graph is a central measure of sparseness in extremal graph theory. In 1966, Erdős conjectured that $d$-degenerate bipartite graphs have Turán number...
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SEMINARS, HARVARD-MIT COMBINATORICS
April 17, 2024 4:15 pmTropical intersection theory aims to create analogues of intersection-theoretic tools from algebraic geometry in a piecewise-linear setting. In this talk, I’ll describe a few aspects of tropical intersection theory and...
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SEMINARS, HARVARD-MIT COMBINATORICS
April 12, 2024 3:00 pmErdos-Kleitman-Rothschild proved that the number of triangle-free graphs on n vertices is asymptotic to the number of bipartite graphs; or in other words, a typical triangle-free graph is a random...
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SEMINARS, HARVARD-MIT COMBINATORICS
April 10, 2024 4:15 pmFor a poset $P$, Galashin introduced a simple polytope $\mathscr A(P)$ called the $P$-associahedron. We will discuss a simple realization of poset associahedra and show that the $f$-vector of $\mathscr...
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SEMINARS, HARVARD-MIT COMBINATORICS
April 3, 2024 4:15 pmThe derived category of a variety is an important and difficult invariant. In this talk, I discuss a purely convex-geometric and combinatorial approach to these categories for toric varieties. Along...
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SEMINARS, HARVARD-MIT COMBINATORICS
March 27, 2024 4:15 pmSchubert calculus involves studying intersection problems among linear subspaces of C^n. A classical example of a Schubert problem is to find all 2-dimensional subspaces of C^4 which intersect 4 given...
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SEMINARS, HARVARD-MIT COMBINATORICS
March 27, 2024 3:00 pmThere will be Pecha Kucha talks by: Alan Yan, Amanda Burcroff, Chris Eur, Colin Defant, Grant Barkley, Jiyang Gao, Jon Boretsky, Victor Wang, and Yuhan Jiang. =============================== For more info,...
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SEMINARS, HARVARD-MIT COMBINATORICS
March 22, 2024 4:15 pmThe classical Edrei theorem from the 1950's gives a parametrisation for infinite upper-triangular totally positive real Toeplitz matrices by pairs of sequences of positive real parameters with finite sum. These...
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