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DTSTART;TZID=America/Los_Angeles:20230404T121500
DTEND;TZID=America/Los_Angeles:20230404T131000
DTSTAMP:20260622T225712
CREATED:20230112T225942Z
LAST-MODIFIED:20230327T230516Z
UID:3023-1680610500-1680613800@colleges.claremont.edu
SUMMARY:Noise stability of ranked choice voting (Steven Heilman\, USC)
DESCRIPTION:Given votes for candidates\, what is the best way to determine the winner of the election\, if some of the votes have been corrupted or miscounted?  As we saw in Florida in 2000\, where a difference of 537 votes determined the president of the United States\, the electoral college system does not seem to be the best voting method. We will survey some recent progress on the above question along with some open problems. In particular\, we consider which ranked choice voting method is most stable to corrupted or miscounted votes. \nhttps://arxiv.org/abs/2209.11183
URL:https://colleges.claremont.edu/ccms/event/antc-talk-steven-heilman-usc/
LOCATION:Davidson Lecture Hall\, CMC\, 340 E 9th St\, Claremont\, CA\, 91711\, United States
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20230328T121500
DTEND;TZID=America/Los_Angeles:20230328T131000
DTSTAMP:20260622T225712
CREATED:20230124T212708Z
LAST-MODIFIED:20230320T225330Z
UID:3054-1680005700-1680009000@colleges.claremont.edu
SUMMARY:The Smith normal form of a polynomial of a random integral matrix (Gilyoung Cheong\, UC Irvine)
DESCRIPTION:Given a prime p\, let P(t) be a non-constant monic polynomial in t over the ring of p-adic integers. Let X(n) be an n x n uniformly random (0\,1)-matrix over the same ring. We compute the asymptotic distribution of the cokernel of P(X(n)) as n goes to infinity. When P(t) is square-free modulo p\, this lets us compute the asymptotic distribution of the Smith normal form of P(X(n)). In fact\, we shall consider the same problem with a more general random matrix X(n)\, which also includes the example of a Haar-random matrix. Our work crucially uses a recent work of W. Sawin and M. M. Wood which shows that the moments of finite size modules over any ring determine their distribution.\n\nThis is joint work with Myungjun Yu. https://arxiv.org/abs/2303.09125
URL:https://colleges.claremont.edu/ccms/event/antc-talk-gilyoung-cheong-uci/
LOCATION:Davidson Lecture Hall\, CMC\, 340 E 9th St\, Claremont\, CA\, 91711\, United States
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20230321T121500
DTEND;TZID=America/Los_Angeles:20230321T131000
DTSTAMP:20260622T225712
CREATED:20230113T153459Z
LAST-MODIFIED:20230313T193754Z
UID:3025-1679400900-1679404200@colleges.claremont.edu
SUMMARY:Robust properties of graphs (Asaf Ferber\, UC Irvine)
DESCRIPTION:In this talk we will consider some notions of `robustness’ of graph/hypergraph properties. We will survey some existing results and will try to emphasize the following new result (joint with Adva Mond and Kaarel Haenni): The binomial random digraph $D_{n\,p}$ typically contains the minimum between the minimum out- and in-degrees many edge-disjoint Hamilton cycles\, given that $p\geq \log^C n/n$. The result is optimal up to log factors.
URL:https://colleges.claremont.edu/ccms/event/antc-talk-asaf-ferber-uc-irvine/
LOCATION:Davidson Lecture Hall\, CMC\, 340 E 9th St\, Claremont\, CA\, 91711\, United States
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20230221T121500
DTEND;TZID=America/Los_Angeles:20230221T131000
DTSTAMP:20260622T225712
CREATED:20230201T215846Z
LAST-MODIFIED:20230215T012913Z
UID:3065-1676981700-1676985000@colleges.claremont.edu
SUMMARY:On zeros of multilinear polynomials (Max Forst\, CGU)
DESCRIPTION:Consider rational polynomials in multiple variables that are linear with respect to some of the variables. In this talk we discuss the problem of finding a zero of such polynomials that are bounded with respect to a height function. For a system of such polynomials satisfying certain technical conditions we prove the existence of a bounded height simultaneous zero. For a single such polynomial we prove the existence of a zero of bounded height lying outside of a prescribed algebraic set. Based on joint work with Lenny Fukshansky.
URL:https://colleges.claremont.edu/ccms/event/antc-talk-max-forst-cgu-2/
LOCATION:Davidson Lecture Hall\, CMC\, 340 E 9th St\, Claremont\, CA\, 91711\, United States
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20230207T121500
DTEND;TZID=America/Los_Angeles:20230207T131000
DTSTAMP:20260622T225712
CREATED:20230202T190817Z
LAST-MODIFIED:20230202T190817Z
UID:3066-1675772100-1675775400@colleges.claremont.edu
SUMMARY:Orthogonality defect and coherence of cyclotomic lattices (Lenny Fukshansky\, CMC)
DESCRIPTION:There are two different measures of how far a given Euclidean lattice is from being orthogonal — the orthogonality defect and the average coherence. The first of these comes from the study of sphere packing while the second is motivated by frame theory\, but both of them have applications in digital communications\, especially in coding theory and cryptography. It is interesting to understand how the two are related. We investigate this question on an important class of cyclotomic lattices\, where some nice formulas can be derived and certain empirical observations can be made. Joint work with David Kogan.
URL:https://colleges.claremont.edu/ccms/event/orthogonality-defect-and-coherence-of-cyclotomic-lattices-lenny-fukshansky-cmc/
LOCATION:Davidson Lecture Hall\, CMC\, 340 E 9th St\, Claremont\, CA\, 91711\, United States
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20230131T121500
DTEND;TZID=America/Los_Angeles:20230131T131000
DTSTAMP:20260622T225712
CREATED:20230112T013416Z
LAST-MODIFIED:20230112T054807Z
UID:3021-1675167300-1675170600@colleges.claremont.edu
SUMMARY:Biquandle arrow weights (Sam Nelson\, CMC)
DESCRIPTION:Many knot invariants are defined from features of knot projections such as arcs or crossings. Gauss diagrams provide an alternative combinatorial scheme for representing knots. In this talk we will use Gauss diagrams to enhance the biquandle counting invariant for classical and virual knots using biquandle arrow weights\, a new algebraic structure without a clear geometric interpretation. This is joint work with Migiwa Sakurai (Shibaura Institute of Technology\, Tokyo).
URL:https://colleges.claremont.edu/ccms/event/antc-talk-sam-nelson-cmc-3/
LOCATION:Davidson Lecture Hall\, CMC\, 340 E 9th St\, Claremont\, CA\, 91711\, United States
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20221206T121500
DTEND;TZID=America/Los_Angeles:20221206T131000
DTSTAMP:20260622T225712
CREATED:20221130T053013Z
LAST-MODIFIED:20221130T053013Z
UID:3005-1670328900-1670332200@colleges.claremont.edu
SUMMARY:Positive semigroups in lattices and totally real number fields (Lenny Fukshansky\, CMC)
DESCRIPTION:Let  L be a full-rank lattice in R^n and write L+ for the semigroup of all vectors with nonnegative coordinates in L. We call a basis X for L positive if it is contained in L+. There are infinitely many such bases\, and each of them spans a conical semigroup S(X) consisting of all nonnegative integer linear combinations of the vectors of X. Such S(X) is a sub-semigroup of L+\, and we investigate the distribution of the gaps of S(X) in L+\, i.e. points in L+ outside of S(X). We describe some basic properties and counting estimates for these gaps. Our main focus is on the restrictive successive minima of these sets\, for which we produce bounds in the spirit of Minkowski’s successive minima theorem. We apply these results to obtain analogous bounds for the successive minima with respect to Weil height of totally positive sub-semigroups of ideals in totally real number fields. Joint work with Siki Wang (CMC’22).
URL:https://colleges.claremont.edu/ccms/event/positive-semigroups-in-lattices-and-totally-real-number-fields-lenny-fukshansky-cmc/
LOCATION:Davidson Lecture Hall\, CMC\, 340 E 9th St\, Claremont\, CA\, 91711\, United States
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20221129T122500
DTEND;TZID=America/Los_Angeles:20221129T131500
DTSTAMP:20260622T225712
CREATED:20221110T030247Z
LAST-MODIFIED:20221124T032038Z
UID:2989-1669724700-1669727700@colleges.claremont.edu
SUMMARY:Partial orders on standard Young tableaux( Gizem Karaali\, Pomona)
DESCRIPTION:Young diagrams are all possible arrangements of n boxes into rows and columns\, with the number of boxes in each subsequent row weakly decreasing. For a partition λ of n\, a standard Young tableau S of shape λ is built from the Young diagram of shape λ by filling it with the numbers 1 to n\, each occurring exactly once in such a way that the numbers are strictly increasing across rows (left to right) and down columns. Young diagrams with n cells are in one-to-one correspondence with the irreducible representations of the symmetric group Sn\,; the standard Young tableaux count the dimensions of these irreps and thus are some of the most essential objects of combinatorial representation theory and algebraic combinatorics. In this talk\, based on joint work with Isabella Senturia (PO’20) and Müge Taskin\, I will describe a handful of partial orders already defined on SYTn\, the set of all standard Young tableaux with n cells\, and propose a new one.
URL:https://colleges.claremont.edu/ccms/event/antc-talk-gizem-karaali-pomona-2/
LOCATION:On Zoom
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20221115T121500
DTEND;TZID=America/Los_Angeles:20221115T131000
DTSTAMP:20260622T225712
CREATED:20220823T003904Z
LAST-MODIFIED:20221102T220943Z
UID:2786-1668514500-1668517800@colleges.claremont.edu
SUMMARY:Minimal Mahler measure in number fields (Kate Petersen\, University of Minnesota Duluth)
DESCRIPTION:The Mahler measure of a polynomial is the modulus of its leading term multiplied by the moduli of all roots outside the unit circle.  The Mahler measure of an algebraic number b\, M(b) is the Mahler measure of its minimal polynomial. By a result of Kronecker\, an algebraic number b satisfies M(b)=1 if and only if b is a root of unity. Famously\, Lehmer asked if there are algebraic numbers with Mahler measures arbitrarily close to 1 (but not equal to 1). We will investigate the minimal Mahler measure of a number field.  For a number field K this is the smallest Mahler measure of a non-torsion generator for K\, written M(K). There are known upper and lower bounds for M(K) in terms of the degree and discriminant of K.  Focusing on cubics\, we will discuss how these bounds correspond to other properties of the number field\, and the sharpness of these bounds.  This is joint work with Lydia Eldredge.
URL:https://colleges.claremont.edu/ccms/event/antc-talk-kate-petersen-university-of-minnesota-duluth/
LOCATION:Davidson Lecture Hall\, CMC\, 340 E 9th St\, Claremont\, CA\, 91711\, United States
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20221108T121500
DTEND;TZID=America/Los_Angeles:20221108T131000
DTSTAMP:20260622T225712
CREATED:20220824T204820Z
LAST-MODIFIED:20221031T203245Z
UID:2787-1667909700-1667913000@colleges.claremont.edu
SUMMARY:Factoring translates of polynomials (Arvind Suresh\, University of Arizona - Tucson)
DESCRIPTION:Given a degree d polynomial f(x) in Q[x]\, consider the subset S_f  of Q consisting of rational numbers t for which the translated polynomial f(x) – t factors completely in Q[x]. For example\, if f is linear or quadratic then S_f is always infinite\, but if degree of f is at least 3\, then interesting things can happen. In this talk\, we discuss a connection between the set S_f and the classical Prouhet–Tarry–Escott problem (which asks for integer solutions to certain symmetric family of equations)\, and we present two infinite families of polynomials f for which S_f is infinite (upon replacing Q with certain number fields). Time permitting\, we outline how these can then be used to produce algebraic curves over number fields having a record number of rational points (relative to their genus).
URL:https://colleges.claremont.edu/ccms/event/antc-talk-arvind-suresh-university-of-arizona-tucson/
LOCATION:Davidson Lecture Hall\, CMC\, 340 E 9th St\, Claremont\, CA\, 91711\, United States
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20221101T121500
DTEND;TZID=America/Los_Angeles:20221101T131000
DTSTAMP:20260622T225712
CREATED:20220906T211012Z
LAST-MODIFIED:20221031T180722Z
UID:2839-1667304900-1667308200@colleges.claremont.edu
SUMMARY:A tale of two worlds: parking functions &  reduction algebras (Dwight Anderson Williams II\, Pomona)
DESCRIPTION:“A Tale of Two Cities” is a novel told in three books/parts. Here we describe three projects related both to published work and ongoing pieces: \nPROJECT 1: In the world of combinatorics\, parking functions are combinatorial objects arising from the situation of parking cars under a parking strategy. In this part of the talk\, we will refresh the notion of classical parking functions given by the classical parking rules/strategy. We will then state an interesting correspondence between certain classical parking functions and so-called ideal states of the famous Tower of Hanoi game. This work is to appear in The American Mathematical Monthly with the following co-authors: Y. Aguillon\, D. Alvarenga\, P.E. Harris\, S. Kotapati\, J.C. Martinez Mori\, C. Monroe\, Z. Saylor\, and C. Tieu. \nPROJECT 2: In the world of algebra\, we shed light on representation theory of Lie superalgebras by constructing reduction algebras. These algebras provide structures to study in their own right\, and we give an example in presenting the diagonal reduction algebra of $osp(1|2)$\, first described in a joint paper with Jonas T. Hartwig. \nPROJECT 3: Continuing down an algebraic pathway\, we summarize the general framework given by Zhelobenko to apply representation theory of reduction algebras as a method to solve equations. Fixing equations important to the study of physics has led to recent work with Jonas T. Hartwig and Erin Dolecheck\, as well\, Irmak Bukey.
URL:https://colleges.claremont.edu/ccms/event/antc-talk-dwight-anderson-williams-ii-pomona/
LOCATION:Davidson Lecture Hall\, CMC\, 340 E 9th St\, Claremont\, CA\, 91711\, United States
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20221025T121500
DTEND;TZID=America/Los_Angeles:20221025T131000
DTSTAMP:20260622T225712
CREATED:20220906T160323Z
LAST-MODIFIED:20221012T181637Z
UID:2834-1666700100-1666703400@colleges.claremont.edu
SUMMARY:Properties of redistricting Markov chains (Sarah Cannon\, CMC)
DESCRIPTION:Markov chains have become widely-used to generate random political districting plans. These random districting plans can be used to form a baseline for comparison\, and any proposed districting plans that differ significantly from this baseline can be flagged as potentially gerrymandered. However\, very little is rigorously known about these Markov chains – Are they irreducible? What is their mixing time? For some\, even the stationary distribution remains unknown. I will present recent work that answers some of these questions\, which uses tools from probability\, computational geometry\, and more.
URL:https://colleges.claremont.edu/ccms/event/antc-talk-sarah-cannon-cmc/
LOCATION:Davidson Lecture Hall\, CMC\, 340 E 9th St\, Claremont\, CA\, 91711\, United States
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20221011T121500
DTEND;TZID=America/Los_Angeles:20221011T131000
DTSTAMP:20260622T225712
CREATED:20220825T192011Z
LAST-MODIFIED:20221004T211454Z
UID:2794-1665490500-1665493800@colleges.claremont.edu
SUMMARY:On the geometry of lattice extensions (Max Forst\, CGU)
DESCRIPTION:Given a lattice L\, an extension of L is a lattice M of strictly greater rank so that L is equal to the intersection of the subspace spanned by L with M. In this talk\, we will discus constructions of such lattice extensions with particular geometric invariants of M\, such as the determinant\, covering radius and successive minima related to the analogous invariants of L. Joint work with Lenny Fukshansky.
URL:https://colleges.claremont.edu/ccms/event/antc-talk-max-forst-cgu/
LOCATION:Davidson Lecture Hall\, CMC\, 340 E 9th St\, Claremont\, CA\, 91711\, United States
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20221004T121500
DTEND;TZID=America/Los_Angeles:20221004T131000
DTSTAMP:20260622T225712
CREATED:20220829T210323Z
LAST-MODIFIED:20221003T234340Z
UID:2800-1664885700-1664889000@colleges.claremont.edu
SUMMARY:Recent developments on the slice rank polynomial method with applications (Mohamed Omar\, HMC)
DESCRIPTION:The slice rank polynomial method\, motivated by groundbreaking work of Croot\, Lev and Pach and refined by Tao\, has opened the door to the resolution of many problems in extremal combinatorics. We survey these results and discuss contributions in several of the speaker’s recent papers.
URL:https://colleges.claremont.edu/ccms/event/antc-talk-mohamed-omar-hmc/
LOCATION:Davidson Lecture Hall\, CMC\, 340 E 9th St\, Claremont\, CA\, 91711\, United States
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20220927T121500
DTEND;TZID=America/Los_Angeles:20220927T131000
DTSTAMP:20260622T225712
CREATED:20220906T160640Z
LAST-MODIFIED:20220922T053209Z
UID:2836-1664280900-1664284200@colleges.claremont.edu
SUMMARY:Spinning switches on a wreath product (Peter Kagey\, HMC)
DESCRIPTION:This talk discusses a puzzle called “Spinning Switches\,” based on a problem popularized by Martin Gardner in his February 1979 column of “Mathematical Games”. This puzzle can be generalized to a two-player game on a finite wreath products. This talk will provide a classification of several families of these generalized puzzles\, including a full classification in the case of Abelian groups.
URL:https://colleges.claremont.edu/ccms/event/antc-talk-peter-kagey-hmc/
LOCATION:Davidson Lecture Hall\, CMC\, 340 E 9th St\, Claremont\, CA\, 91711\, United States
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20220920T121500
DTEND;TZID=America/Los_Angeles:20220920T131000
DTSTAMP:20260622T225712
CREATED:20220811T002022Z
LAST-MODIFIED:20220906T231455Z
UID:2780-1663676100-1663679400@colleges.claremont.edu
SUMMARY:Arithmetical structures (Luis Garcia Puente\, Colorado College)
DESCRIPTION:An arithmetical structure on a finite\, connected graph G without loops is given by an assignment of positive integers to the vertices such that\, at each vertex\, the integer there is a divisor of the sum of the integers at adjacent vertices\, counted with multiplicity if the graph is not simple. Alternatively\,  an arithmetical structure on G is a pair  of positive integer vectors (d\,r) such that  Mr = 0\, where M = diag(d) – A  is a square matrix whose diagonal entries are given by the vector d\, and whose off-diagonal elements are given by the negative adjacency matrix of G. Arithmetical structures were first introduced by Lorenzini in 1989; matrices of the form (diag(d) – A) arise in algebraic geometry as intersection matrices of degenerating curves.  However\, they also naturally appear in the context of algebraic graph theory as matrices of the form  (diag(d) – A)  generalize the Laplacian matrix of a graph.\n\nIn this talk\, I will give an introduction to the topic. We will discuss some combinatorial\, structural and computational aspects of arithmetical structures. In particular\, we will count the number of distinct arithmetical structures on certain graph families such as path\, cycle\, complete and bident graphs. For paths\, we will show that arithmetical structures are enumerated by the Catalan numbers. For cycles\, we prove that arithmetical structures are enumerated by the binomial coefficients C(2n-1\,n-1).  We will also discuss results about the associated critical group of an arithmetical structure\, i.e.\,  the cokernel of the matrix M.   This talk will be accessible to undergraduate students with some knowledge of linear algebra and discrete mathematics.
URL:https://colleges.claremont.edu/ccms/event/antc-talk-luis-garcia-puente-colorado-college/
LOCATION:Davidson Lecture Hall\, CMC\, 340 E 9th St\, Claremont\, CA\, 91711\, United States
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20220913T121500
DTEND;TZID=America/Los_Angeles:20220913T131000
DTSTAMP:20260622T225712
CREATED:20220902T001706Z
LAST-MODIFIED:20220906T231347Z
UID:2814-1663071300-1663074600@colleges.claremont.edu
SUMMARY:Kriz's theorem via dynamics of linear operators (Yunied Puig de Dios\, CMC)
DESCRIPTION:The existence of a set $A\subset \N_0$ of positive upper Banach density such that $A-A:=\{m-n:m\, n\in A\, m>n\}$ does not contain a set of the form $S-S$ with $S$ a piecewise syndetic is in essence the content of a popular result due to K\v r\'{i}\v z in 1987. Since then at least four different proofs of this result have been given\, and all of them give basically the example originally exhibited by K\v r\'{i}\v z when viewed appropriately. We obtain a generalization of K\v r\'{i}\v z’s result. Our approach differs completely from the previous ones\, as this would be the first proof of K\v r\'{i}\v z’s Theorem which does not rely on Lov\'{a}sz’s Theorem for chromatic numbers of Kneser graphs. Furthermore\, it is done via operator theory\, namely using dynamics of bounded linear operators on infinite-dimensional complex separable Banach spaces. As a consequence\, our example is genuinely different from the one exhibited  originally by K\v r\'{i}\v z.
URL:https://colleges.claremont.edu/ccms/event/krizs-theorem-via-dynamics-of-linear-operators-yunied-puig-de-dios-cmc/
LOCATION:Davidson Lecture Hall\, CMC\, 340 E 9th St\, Claremont\, CA\, 91711\, United States
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20220906T121500
DTEND;TZID=America/Los_Angeles:20220906T131000
DTSTAMP:20260622T225712
CREATED:20220811T001752Z
LAST-MODIFIED:20220902T173415Z
UID:2779-1662466500-1662469800@colleges.claremont.edu
SUMMARY:Monodromy groups of Belyi Lattes maps (Edray Goins\, Pomona College)
DESCRIPTION:An elliptic curve $ E: y^2 + a_1 \\, x \\, y + a_3 \\, y = x^3 + a_2 \\, x^2 + a_1 \\, x + a_6 $ is a cubic equation which has two curious properties: (1) the curve is nonsingular\, so that we can draw tangent lines to every point $ P = (x\,y) $ on the curve; and (2) the collection of complex points\, namely $ E(\mathbb C) $\, forms an abelian group under a certain binary operation $ \bigoplus: E(\mathbb C) \times E(\mathbb C) \to E(\mathbb C) $.   In particular\, for every positive integer $N$\, the map $ P \mapsto [N] P $ which adds a point $ P \in E(\mathbb C) $ to itself $N$ times is a group homomorphism.   A rational map $\gamma: \mathbb P^1(\mathbb C) \to \mathbb P^1(\mathbb C) $ from the Riemann Sphere to itself is said to be a Latt\`{e}s Map if there are “well-behaved” maps $ \phi: E(\mathbb C) \to \mathbb P^1(\mathbb C) $ and $\psi: E(\mathbb C) \to E(\mathbb C) $ such that $\gamma \circ \phi = \phi \circ \psi$.  We are interested in those Latt\`{e}s Maps $\gamma$ which are also Bely\u{\i} Maps\, that is\, the only critical values are $ 0 $\, $ 1 $\, and $ \infty $.  Work of Zeytin classifies all such maps: For example\, if $ E: y^2 = x^3 + 1 $ then $ \phi: (x\,y) \mapsto (y+1)/2 $ while $\psi = [N] $ for some positive integer $N$.\n\nWe would like to know more about Bely\u{\i} Latt\`{e}s Maps $\gamma$.  What can we say about such maps?  What are their Dessin d’Enfants?  In some cases\, this is a bipartite graph with $ 3 \\, N^2 $ vertices.  What are their monodromy groups? Sometimes this is a group of size $ 3 \\, N^2 $.  In this talk\, we explain the complete answers to these questions\, exploiting the relationship between fundamental groups of Riemann surfaces and Galois groups of function fields.  This work is conducted as part of the Pomona Research in Mathematics Experience (DMS-2113782).
URL:https://colleges.claremont.edu/ccms/event/monodromy-groups-of-belyi-lattes-maps-edray-goins-pomona-college/
LOCATION:Estella 1021 (Emmy Noether Room)\, Pomona College\, Claremont\, CA\, 91711\, United States
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20220503T123000
DTEND;TZID=America/Los_Angeles:20220503T132000
DTSTAMP:20260622T225712
CREATED:20220128T185315Z
LAST-MODIFIED:20220418T040129Z
UID:2583-1651581000-1651584000@colleges.claremont.edu
SUMMARY:Beran’s tests of uniformity for discrete data (Michael Orrison\, HMC)
DESCRIPTION:Suppose you are given a data set that can be viewed as a nonnegative integer-valued function defined on a finite set. A natural question to ask is whether the data can be viewed as a sample from the uniform distribution on the set\, in which case you might want to apply some sort of test of uniformity to the data. In this talk\, I will share some work Anna Bargagliotti (Loyola Marymount University) and I have been doing to better understand a particular class of tests of uniformity first described in a 1968 paper written by R.J. Beran. Our approach uses tools from harmonic analysis on finite groups\, and in this talk I will introduce those tools and then show how they can easily be used when working with discrete circular data.
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-michael-orrison-hmc/
LOCATION:On Zoom
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20220426T123000
DTEND;TZID=America/Los_Angeles:20220426T132000
DTSTAMP:20260622T225712
CREATED:20220127T053038Z
LAST-MODIFIED:20220421T192843Z
UID:2570-1650976200-1650979200@colleges.claremont.edu
SUMMARY:Bounds for nonzero Littlewood-Richardson coefficients (Müge Taskin\, Boğaziçi University\, Turkey)
DESCRIPTION:As  $\lambda$ runs through all integer partitions\, the set of   Schur functions $\{s_{\lambda}\}_\lambda$ forms a basis in the ring of symmetric functions. Hence the rule $$s_{\lambda}s_{\mu}=\sum c_{\lambda\,\mu}^{\gamma} s_{\gamma}$$ makes sense and the coefficients $c_{\lambda\,\mu}^{\gamma}$ are called \textit{Littlewood-Richardson (LR) coefficients}. The calculations of Littlewood-Richardson coefficients has been an important problem from the first time they were introduced\, due to their important role in representation theory of symmetric groups and enumerative geometry. \nIn this talk we will explain some of the main features of these coefficients and provide a summary of the characterizations given by Littlewood and Richardson (1934)\, Berenstein- Zelevinsky ()1988) and Knutson-Tao (1999). Then we will explain our approach to a seemingly easier problem\, that is\, the determination of  triples $(\lambda\,\mu\,\gamma)$  of partitions for which $c_{\lambda\,\mu}^{\gamma}$ is non zero. Our method describes some upper and lower bounds for triples $(\lambda\,\mu\,\gamma)$ with nonzero  $c_{\lambda\,\mu}^{\gamma}$\, by using  Young diagram combinatorics and especially\, the indispensable Dominance order. This is joint work with R. Bedii Gümüş and supported by Tübitak/1001/115F156.
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-muge-taskin-bogazici-university-turkey/
LOCATION:On Zoom
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20220419T123000
DTEND;TZID=America/Los_Angeles:20220419T132000
DTSTAMP:20260622T225712
CREATED:20220124T234622Z
LAST-MODIFIED:20220413T160024Z
UID:2553-1650371400-1650374400@colleges.claremont.edu
SUMMARY:A conjugacy criterion for two pairs of 2 x 2 matrices over a commutative ring (Bogdan Petrenko\, Eastern Illinois University)
DESCRIPTION:I will explain how to apply presentations of algebras (together with some classical results from non-commutative algebra) to obtain some 5 polynomial invariants telling us when two pairs of 2×2 matrices over a commutative ring are conjugate\, assuming that each of these pairs generate the matrix algebra. This talk is based on my joint paper with Marcin Mazur (Binghamton University):  Separable algebras over infinite fields are 2-generated and finitely presented\, Arch. Math. 93 (2009)\, 521-529.
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-bogdan-petrenko-eastern-illinois-university/
LOCATION:On Zoom
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20220412T123000
DTEND;TZID=America/Los_Angeles:20220412T132000
DTSTAMP:20260622T225712
CREATED:20211213T015630Z
LAST-MODIFIED:20220225T220354Z
UID:2510-1649766600-1649769600@colleges.claremont.edu
SUMMARY:Geometrization of Markov numbers (Oleg Karpenkov\, University of Liverpool)
DESCRIPTION:In this talk we link discrete Markov spectrum to geometry of continued fractions. As a result of that we get a natural generalization of classical Markov tree which leads to an efficient computation of Markov minima for all elements in generalized Markov trees.
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-oleg-karpenkov-university-of-liverpool/
LOCATION:TBA
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20220405T123000
DTEND;TZID=America/Los_Angeles:20220405T132000
DTSTAMP:20260622T225712
CREATED:20220125T062030Z
LAST-MODIFIED:20220326T052025Z
UID:2556-1649161800-1649164800@colleges.claremont.edu
SUMMARY:Covering by polynomial planks (Alexey Glazyrin\, University of Texas Rio Grande Valley)
DESCRIPTION:In 1932\, Tarski conjectured that a convex body of width 1 can be covered by planks\, regions between two parallel hyperplanes\, only if the total width of planks is at least 1. In 1951\, Bang proved the conjecture of Tarski. In this work we study the polynomial version of Tarski’s plank problem. \nWe note that the recent polynomial proofs of the spherical and complex plank covering problems by Zhao and Ortega-Moreno give some general information on zeros of real and complex polynomials restricted to the unit sphere. As a corollary of these results\, we establish several generalizations of the Bang plank covering theorem.\nUsing the polynomial approach\, we also prove the strengthening of the Fejes Tóth zone conjecture on covering a sphere by spherical segments\, closed parts of the sphere between two parallel hyperplanes. In particular\, we show that the sum of angular widths of spherical segments covering the whole sphere is at least π. \nThis is a joint work with Roman Karasev and Alexandr Polyanskii.
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-alexey-glazyrin-university-of-texas-rio-grande-valley/
LOCATION:On Zoom
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20220329T123000
DTEND;TZID=America/Los_Angeles:20220329T132000
DTSTAMP:20260622T225712
CREATED:20220127T202631Z
LAST-MODIFIED:20220326T051329Z
UID:2573-1648557000-1648560000@colleges.claremont.edu
SUMMARY:Peg solitaire in multiple colors on graphs (Tara Davis\, Hawaii Pacific University and Roberto Soto\, Cal State Fullerton)
DESCRIPTION:Peg solitaire is a popular one person board game that has been played in many countries on various board shapes. Recently\, peg solitaire has been studied extensively in two colors on mathematical graphs. We will present our rules for multiple color peg solitaire on graphs. We will present some student and faculty results classifying the solvability of the game on several graceful graphs\, as well as discuss open questions.
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-tara-davis-hawaii-pacific-university-and-roberto-soto-cal-state-fullerton/
LOCATION:On Zoom
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20220322T123000
DTEND;TZID=America/Los_Angeles:20220322T132000
DTSTAMP:20260622T225712
CREATED:20220128T031313Z
LAST-MODIFIED:20220321T182413Z
UID:2575-1647952200-1647955200@colleges.claremont.edu
SUMMARY:Continuous extensions of Ramanujan-expandable arithmetic functions (Matthew Fox\, Perimeter Institute for Theoretical Physics and Chai Karamchedu\, Sandia National Labs)
DESCRIPTION:We describe a natural way to continuously extend arithmetic functions that admit a Ramanujan expansion and derive the conditions under which such an extension exists. In particular\, we show that the absolute convergence of a Ramanujan expansion does not guarantee the convergence of its real variable generalization. We take the divisor function as a case study\, and consider how to continuously extend it to the reals.
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-matthew-fox-perimeter-institute-for-theoretical-physics-and-chai-karamchedu-sandia-national-labs/
LOCATION:On Zoom
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20220308T123000
DTEND;TZID=America/Los_Angeles:20220308T132000
DTSTAMP:20260622T225712
CREATED:20220112T041154Z
LAST-MODIFIED:20220222T011851Z
UID:2527-1646742600-1646745600@colleges.claremont.edu
SUMMARY:Equidistribution of norm 1 elements in cyclic number fields (Kate Petersen\, University of Minnesota Duluth)
DESCRIPTION:By Hilbert’s theorem 90\, if K is a cyclic number field with Galois group generated by g\, then any element of norm 1 can be written as a/g(a).  This gives rise to a natural height function on elements of norm 1.  I’ll discuss equidistribution problems and show that these norm 1 elements are equidistributed (in an appropriate quotient) with respect to this height.
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-kate-petersen-university-of-minnesota-duluth/
LOCATION:On Zoom
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20220301T123000
DTEND;TZID=America/Los_Angeles:20220301T132000
DTSTAMP:20260622T225712
CREATED:20220111T231348Z
LAST-MODIFIED:20220221T211055Z
UID:2524-1646137800-1646140800@colleges.claremont.edu
SUMMARY:Gap theorems for linear forms and for rotations on higher dimensional tori (Alan Haynes\, University of Houston)
DESCRIPTION:This talk is based on joint work with Jens Marklof\, and with Roland Roeder. The three distance theorem states that\, if x is any real number and N is any positive integer\, the points x\, 2x\, … \, Nx modulo 1 partition the unit interval into component intervals having at most 3 distinct lengths. We will present two higher dimensional analogues of this problem. In the first we consider points of the form mx+ny modulo 1\, where x and y are real numbers and m and n are integers taken from an expanding set in the plane. This version of the problem was previously studied by Geelen and Simpson\, Chevallier\, Erdős\, and many other people\, and it is closely related to the Littlewood conjecture in Diophantine approximation. The second version of the problem is a straightforward generalization to rotations on higher dimensional tori which\, surprisingly\, has been mostly overlooked in the literature. For the two dimensional torus\, we are able to prove a five distance theorem\, which is best possible. In higher dimensions we also have bounds\, but establishing optimal bounds is an open problem.
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-alan-haynes-university-of-houston/
LOCATION:On Zoom
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20220215T123000
DTEND;TZID=America/Los_Angeles:20220215T132000
DTSTAMP:20260622T225712
CREATED:20220119T153839Z
LAST-MODIFIED:20220210T023821Z
UID:2540-1644928200-1644931200@colleges.claremont.edu
SUMMARY:Recent trends in using representations in voting theory - committees and cyclic orders (Karl-Dieter Crisman\, Gordon College)
DESCRIPTION:One of the most important axioms in analyzing voting systems is that of “neutrality”\, which stipulates that the system should treat all candidates symmetrically. Even though this doesn’t always directly apply (such as in primary systems or those with intentional incumbent protection)\, it is extremely important both in theory and practice.If the voting systems in question additionally are tabulated using some sort of points\, we can translate the notion of neutrality into invariance under an action of the symmetric group on a vector space. This means we can exploit representation theory to analyze them\, and this has been successfully done in a number of social choice contexts from cooperative games to voting on full rankings.In this talk\, we describe recent progress in extending this technique to two interesting situations. First we consider work of Barcelo et al. on voting for committees of representatives (such as for departments in a college)\, where the wreath product of two symmetric groups comes into play. Then we look at work by Crisman et al. regarding voting on “cyclic orders”\, or ways to seat people around a table\, which implicitly has both left and right actions of the symmetric group to consider.
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-karl-dieter-crisman-gordon-college/
LOCATION:On Zoom
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20220208T123000
DTEND;TZID=America/Los_Angeles:20220208T132000
DTSTAMP:20260622T225712
CREATED:20220131T003643Z
LAST-MODIFIED:20220131T003643Z
UID:2585-1644323400-1644326400@colleges.claremont.edu
SUMMARY:Frame coherence and nearly orthogonal lattices (Lenny Fukshansky\, CMC)
DESCRIPTION:A frame in a Euclidean space is a spanning set\, which can be overdetermined. Large frames are used for redundant signal transmission\, which allows for error correction. An important parameter of frames is coherence\, which is maximal absolute value of the cosine of the angle between two frame vectors: the smaller it is\, the closer is the frame to being orthogonal\, which minimizes noise from overlapping frequencies in transmission. One good source frames with sufficiently low coherence comes from layers of minimal vectors in a lattice. We will discuss a particular class of so-called nearly orthogonal lattices\, which exhibits some interesting properties from the stand-point of coherence and other related optimization problems. This is joint work with David Kogan (CGU).
URL:https://colleges.claremont.edu/ccms/event/frame-coherence-and-nearly-orthogonal-lattices-lenny-fukshansky-cmc/
LOCATION:On Zoom
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20220201T123000
DTEND;TZID=America/Los_Angeles:20220201T132000
DTSTAMP:20260622T225712
CREATED:20220121T001428Z
LAST-MODIFIED:20220126T183034Z
UID:2543-1643718600-1643721600@colleges.claremont.edu
SUMMARY:Niho's last conjecture (Daniel Katz\, Cal State Northridge)
DESCRIPTION:A power permutation of a finite field F is a permutation of F whose functional form is x -> x^d for some exponent d.  Power permutations are used in cryptography\, and the exponent d must be chosen so that the permutation is highly nonlinear\, that is\, not easily approximated by linear functions.  The Walsh spectrum of a power permutation is a list of numbers measuring the correlation of our power permutation with the various linear functions. The last conjecture in Niho’s 1972 thesis considers a particular infinite family of highly nonlinear power permutations\, and states that each permutation in this family has a Walsh spectrum with at most five distinct values. Niho’s own techniques show that there are at most eight distinct values. Each of the eight candidate values corresponds to a possible number of distinct roots of a seventh degree polynomial on a subset of the finite field F called the unit circle. We use symmetry arguments to show that it is impossible to have four\, six\, or seven roots on the unit circle: this proves Niho’s last conjecture. This is joint work with Tor Helleseth and Chunlei Li.
URL:https://colleges.claremont.edu/ccms/event/antc-talk-daniel-katz-cal-state-northridge/
LOCATION:On Zoom
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
END:VCALENDAR