Differences

This shows you the differences between two versions of the page.

--- seminars:comb:start [2026/03/16 22:33] – [SPRING 2026] zaslav
+++ seminars:comb:start [2026/05/04 19:17] (current) – laura
@@ Line 17: / Line 17: @@
 ===== SPRING 2026 =====
-Anticipated speakers:  Stefan Viola (Binghamton), Ernesto Estrada (Campus Universitat Illes Balears), Alireza Salahshoori (Binghamton)
+Anticipated speakers:  Stefan Viola (Binghamton), Ernesto Estrada (Campus Universitat Illes Balears)
 ----
@@ Line 105: / Line 105: @@
 Location:  WH 100E
-I will explain a connection between algebra derived from graphs and the graph property of maximum matching.
+For a simple graph G, the edge ideal I(G) over a field K is a monomial ideal generated by the edges of G. The associated primes of powers of such ideals form an ascending chain. In this talk, I prove a key ingredient of this result, concerning maximum matchings of graphs derived from G. The talk is based on a paper by Martínez-Bernal, Morey, and Villarreal (2012).
 <HTML><li></HTML>
 **Tuesday, 3/24**\\
 Speaker: Thomas Martinez (UCLA and Cornell) \\
-Title: The Combinatorics of Affine Deodhar Diagrams
+Title: The Combinatorics of Affine Deodhar Diagrams\\
-\\
 Time: 1:30-2:30\\
 Location:  WH 100E
 Deodhar diagrams (also known as Go diagrams) have been studied due to their relation to the totally non-negative Grassmannian and positroid varieties. In this talk, we introduce affine Deodhar diagrams and study combinatorial moves of these diagrams. We provide geometric analogues of our combinatorial moves, discussing the relationship to (affine patches of) positroid varieties and their cluster structure.
@@ Line 124: / Line 125: @@
 **Tuesday, 4/14**\\
 Speaker: Alexander N. Wilson (York and Binghamton)\\
-Title: \\
+Title: Dinv-Zero Fubini Rankings are Pieces of Cake\\
 Time: 1:30-2:30\\
 Location:  WH 100E
+I will begin with some background on the significance of parking functions in representation theory and some statistics on parking functions arising in this context. I will then focus on a recent project that restricts to a subset of parking functions called Fubini rankings and discuss a surprising result relating enumeration in this subset to the number of regions in a simple hyperplane arrangement.
 <HTML><li></HTML>
 **Tuesday, 4/21**\\
 Speaker: Xiyong Yan (Binghamton)\\
-Title: Candidacy exam\\
+Title: Extremal Problems for Unbalanced Signed Graphs and Bipartite Signed Graphs\\
-Time: 1:30-2:30\\
+Time: 1:30-2:30 and 2:30-3:30\\
-Location:  WH 100E
+Location:  WH 100E and WH 309
+I will mainly discuss the paper “Unbalanced Signed Graphs with Extremal Spectral Radius or Index” by Brunetti and Stanić. In that paper, the authors determine the signed graphs attaining the minimum and maximum spectral radius, as well as the minimum and maximum index, among all connected unbalanced signed graphs of order n. In particular, they identify the extremal graphs up to switching isomorphism and provide explicit descriptions of the corresponding extremal values.
+I will also discuss related work from the paper “On the Spectral Radius of Unbalanced Signed Bipartite Graphs” by Conde, Dratman, and Grippo. In that paper, the authors determine, up to switching, the unique unbalanced signed bipartite graph on n vertices with maximum spectral radius, and they study complete bipartite signed graphs whose negative edges induce a tree
+This is Mr. Yan's candidacy exam.  The examining committee consists of Laura Anderson, Michael Dobbins, and Thomas Zaslavsky (chair).  The talks are open to all.
 <HTML><li></HTML>
 **Tuesday, 4/28**\\
-Speaker: \\
+Speaker: Alireza Salahshoori (Binghamton)\\
-Title: Candidacy exam?\\
+Title: Error-Correcting Codes, Matraids, and Signed Graohs\\
-Time: 1:30-2:30\\
+Time: 1:30-2:30 and 2:45-3:45\\
-Location:  WH 100E
+Location:  WH 100E and WH 309
+This talk is based on Victor Wei, "Generalized Hamming Weights for Linear Codes" (1991), and José Martínez-Bernal, Miguel A. Valencia-Bucio, and Rafael H. Villarreal, "Linear Codes over Signed Graphs" (2019).
+This is Mr. Salahshoori's candidacy exam.  The examining committee consists of Laura Anderson, Michael Dobbins, and Thomas Zaslavsky (chair).  The talks are open to all.
 <HTML><li></HTML>
 **Tuesday, 5/5**\\
 Speaker: Danika Van Niel (Binghamton) \\
-Title: \\
+Title: How Compatible Pairs of Transfer Systems Witness Equivariant Structure\\
 Time: 1:30-2:30\\
 Location:  WH 100E
+Transfer systems are combinatorial objects that encode information about equivariant operations. More precisely, a transfer system encodes the transfers (or wrong-way maps) carried by algebras over certain equivariant operads. Thus, transfer systems allow us to use combinatorial tools to study equivariant homotopy theory. Compatible pairs of transfer systems, which are a pair of transfer systems satisfying certain conditions, correspond to multiplicative structures compatible with an underlying additive structure. In particular, compatible pairs are closely related to equivariant operads, ring spectra, bi-incomplete Tambara functors, and model structures. In this talk we introduce transfer systems, compatible pairs, and discuss several properties of transfer systems and their compatible pairs which help us better understand the equivariant objects and structures mentioned above.
+Most of the work discussed in this talk began as a collaboration through the Women in Topology workshop and is joint with Kristen Mazur, Angélica M. Osorno, Constanze Roitzheim, Rekha Santhanam, and Valentina Zapata Castro. The other work discussed in this talk are from a collaboration with Sarah Klanderman, Chloe Lewis, Harlea Monson, and Koki Shibata, as well as a collaboration with David DeMark, Michael Hill, Yigal Kamel, Nelson Niu, Kurt Stoeckl, and Guoqi Yan.
 <HTML><li></HTML>
-**Thursday, 5/7 (Colloquium)**\\
+**Thursday, 5/7 (Colloquium) Special Day**\\
 Speaker: Isabella Novik (Washington) \\
-Title: \\
+Title: Lower bounds on face numbers\\
-Time: \\
+Time: 2:45 pm -- 3:45 pm **Special Time**\\
 Location:  WH 100E
+In this talk, I will discuss several approaches to studying the face numbers of simplicial complexes, with a particular focus on obtaining lower bounds. These approaches include classical rigidity theory, Stanley-Reisner rings, and higher‑dimensional stress spaces. I will also describe a number of both classical and recent results on face numbers that have been obtained using these tools.\\
 <HTML></li></HTML>