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DTSTART;TZID=America/Los_Angeles:20241022T121500
DTEND;TZID=America/Los_Angeles:20241022T131000
DTSTAMP:20260429T030740
CREATED:20240909T190346Z
LAST-MODIFIED:20241016T201124Z
UID:3502-1729599300-1729602600@colleges.claremont.edu
SUMMARY:Making sandwiches: a novel invariant in D-module theory (David Lieberman\, HMC)
DESCRIPTION:In the field of commutative algebra\, the principal object of study is (unsurprisingly) commutative algebras. A somewhat unintuitive fact is that results about commutative algebras can be gleaned from an associated non-commutative algebra whose generators are very analytic in nature. This object is called the ring of differential operators\, often denoted by D. In a sense gives an algebraic way of constructing the partial derivative.\n\nAn important result in the study of D-modules is Bernstein’s inequality\, first proved by Joseph Bernstein in the 1970’s. The result gives a lower bound on the filtered dimension of a D-module\, which a provide insights about modules of commutative algebras. The goal of this talk is to present some novel singular settings where this inequality holds. To do this\, we will introduce an invariant called sandwich Bernstein-Sato polynomials. These are analogous to a well studied object called the Bernstein-Sato polynomial\, which is a generalization of the power rule taught in undergraduate calculus courses. Using sandwich Bernstein-Sato polynomials\, we will show that Bernstein’s inequality holds true for the differential operators of the coordinate ring of the Segre product of projective spaces.
URL:https://colleges.claremont.edu/ccms/event/antc-talk-david-lieberman-hmc/
LOCATION:Estella 2113
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20241008T121500
DTEND;TZID=America/Los_Angeles:20241008T131000
DTSTAMP:20260429T030740
CREATED:20240901T163937Z
LAST-MODIFIED:20240929T202957Z
UID:3482-1728389700-1728393000@colleges.claremont.edu
SUMMARY:Counting matrix points via lattice zeta functions (Yifeng Huang\, USC)
DESCRIPTION:​I will introduce two general problems and explain how they surprisingly connect with each other and with other aspects of mathematics (for a glimpse\, Sato—Tate\, hypergeometric functions\, moduli spaces of sheaves\, Catalan numbers\, Hall polynomials\, etc.)​.\n\nThe first problem is to count finite-field points on so called “varieties of matrix points”. They are created from a simple and fully elementary recipe and can yet easily get very complicated. The second problem is analogous to counting full-rank sublattices of $\mathbb{Z}^d$ with index $n$\, but with $\mathbb{Z}$ replaced by non-Dedekind rings\, such as non-maximal orders in number fields. (Containing joint work with Ken Ono\, Hasan Saad and joint work with Ruofan Jiang)
URL:https://colleges.claremont.edu/ccms/event/antc-talk-yifeng-huang-usc/
LOCATION:Estella 2113
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20241001T121500
DTEND;TZID=America/Los_Angeles:20241001T131000
DTSTAMP:20260429T030740
CREATED:20240827T194511Z
LAST-MODIFIED:20241001T153641Z
UID:3473-1727784900-1727788200@colleges.claremont.edu
SUMMARY:Adinkras as Origami? (Edray Goins\, Pomona College)
DESCRIPTION:Around 20 years ago\, physicists Michael Faux and Jim Gates invented Adinkras as a way to better understand Supersymmetry.  These are bipartite graphs whose vertices represent bosons and fermions and whose edges represent operators which relate the particles.  Recently\, Charles Doran\, Kevin Iga\, Jordan Kostiuk\, Greg Landweber and Stefan M\'{e}ndez-Diez determined that Adinkras are a type of Dessin d’Enfant; they showed this by explicitly exhibiting a Belyi map as a composition $\beta: S \to \mathbb P^1(\mathbb C) \to \mathbb P^1(\mathbb C)$.  They computed the first arrow as a map from a certain compact connected Riemann surface $S$ to the Riemann sphere $\mathbb P^1(\mathbb C) \simeq S^2(\mathbb R)$\, and the second as a map which keeps track of the “coloring” of the edges.\n\nAdinkras naturally have square faces.  This keeps track of the non-commutative nature of the supersymmetric operators.  While Dessin d’Enfants correspond to triangular tilings of Riemann surfaces\, there is a similar construction — called “origami” — which correspond to square tilings.  In this project\, we attempt to discover how to express the construction of Doran\, et al. as a composition $\beta: S \to E(\mathbb C) \to \mathbb P^1(\mathbb C)$ for some elliptic curve elliptic curve $E$ such that the map corresponds to an “origami”\, that is\, a map which is branched over just one point.  This work is conducted as part of the Pomona Research in Mathematics Experience (DMS-2113782).
URL:https://colleges.claremont.edu/ccms/event/adinkras-as-origami-edray-goins-pomona-college/
LOCATION:Estella 2113
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20240924T121500
DTEND;TZID=America/Los_Angeles:20240924T131000
DTSTAMP:20260429T030740
CREATED:20240825T022324Z
LAST-MODIFIED:20240825T022447Z
UID:3467-1727180100-1727183400@colleges.claremont.edu
SUMMARY:Presentations of derived categories (Reginald Anderson\, CMC)
DESCRIPTION:A modification of the cellular resolution of the diagonal given by Bayer-Popescu-Sturmfels gives a virtual resolution of the diagonal for smooth projective toric varieties and toric Deligne-Mumford stacks which are a global quotient of a smooth projective variety by a finite abelian group. In the past year\, Hanlon-Hicks-Lazarev gave a minimal resolution of the diagonal for toric subvarieties of smooth projective toric varieties. We give implications for exceptional collections on smooth projective toric Fano varieties in dimensions 1-4. This is joint work with CMC undergrads Justin Son\, Hill Zhang\, and Jumari Querimit-Ramirez.
URL:https://colleges.claremont.edu/ccms/event/localization-techniques-in-equivariant-cohomology-reginald-anderson-cmc/
LOCATION:Estella 2099
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20240917T121500
DTEND;TZID=America/Los_Angeles:20240917T131000
DTSTAMP:20260429T030740
CREATED:20240824T183435Z
LAST-MODIFIED:20240906T183313Z
UID:3464-1726575300-1726578600@colleges.claremont.edu
SUMMARY:Biquandle module quiver representations (Sam Nelson\, CMC)
DESCRIPTION:Biquandle module enhancements are invariants of knots and links generalizing the classical Alexander module invariant. A quiver categorification of these invariants was introduced in 2020. In this work-in-progress (joint with Yewon Joung from Hanyang University in Seoul) we take the next step by defining invariant quiver representations. As an application we obtain new polynomial knot invariants as decategorifications.
URL:https://colleges.claremont.edu/ccms/event/antc-talk-sam-nelson-cmc-4/
LOCATION:Estella 2113
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20240910T121500
DTEND;TZID=America/Los_Angeles:20240910T131000
DTSTAMP:20260429T030740
CREATED:20240825T022632Z
LAST-MODIFIED:20240906T182843Z
UID:3469-1725970500-1725973800@colleges.claremont.edu
SUMMARY:Localization techniques in equivariant cohomology (Reginald Anderson\, CMC)
DESCRIPTION:In order to understand a topological space X\, it is often easier to understand X in terms of an action by a group G. When X is a compact complex manifold\, we often let G be products of S^1 or \C^* acting in a nice way (“holomorphically”) on X. This simplifies several calculations of an Euler characteristic by considering the torus-fixed loci; examples are given throughout.\n\nThe notes for this talk can be found here:\n\nhttps://drive.google.com/file/d/1FjhKDeJLIPQBlLA-x-BsnkosNayZMSAn/view?usp=sharing
URL:https://colleges.claremont.edu/ccms/event/localization-techniques-in-equivariant-cohomology-reginald-anderson-cmc-2/
LOCATION:Estella 2113
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20240903T121500
DTEND;TZID=America/Los_Angeles:20240903T131000
DTSTAMP:20260429T030740
CREATED:20240824T184428Z
LAST-MODIFIED:20240824T184428Z
UID:3465-1725365700-1725369000@colleges.claremont.edu
SUMMARY:Lattice angles and quadratic forms (Lenny Fukshansky\, CMC)
DESCRIPTION:What are the possible angles between two integer vectors in R^n? If we fix one such possible angle and one integer vector x\, is there always another integer vector y that makes this angle with x? Assuming that x makes a given angle with some vector\, how can we find the shortest such vector y? What if we designate a forbidden set of vectors\, what is the shortest y making a given angle with x outside of this forbidden set? It turns out that all of these questions can be reformulated in terms of a search for zeros of integral quadratic forms\, a rich arithmetic theory. We will give an introduction to this research direction and also show some of our recent results. Joint work with Sehun Jeong (CGU).
URL:https://colleges.claremont.edu/ccms/event/lattice-angles-and-quadratic-forms-lenny-fukshansky-cmc/
LOCATION:Estella 2099
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20240430T121500
DTEND;TZID=America/Los_Angeles:20240430T131000
DTSTAMP:20260429T030740
CREATED:20240212T222657Z
LAST-MODIFIED:20240424T225203Z
UID:3383-1714479300-1714482600@colleges.claremont.edu
SUMMARY:Negligible cohomology (Matthew Gherman\, Caltech)
DESCRIPTION:For a finite group G\, a G-module M\, and a field F\, an element u in H^d(G\,M) is negligible over F if for each field extension L/F and every continuous group homomorphism from Gal(L^{sep}/L) to G\, u is in the kernel of the induced homomorphism H^d(G\,M) to H^d(L\,M). Negligible cohomology was first introduced by Serre and has deep connections with the embedding problem\, cohomological invariants\, and the profinite inverse Galois problem. Professor Alexander Merkurjev (UCLA) and I were able to compute negligible cohomology in degree 2\, compute the mod p negligible cohomology of elementary abelian p-groups\, and determine the Krull dimension of the quotient of mod p cohomology by the ideal of negligible elements.
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-matthew-gherman-cal-tech/
LOCATION:Estella 2099
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20240423T121500
DTEND;TZID=America/Los_Angeles:20240423T131000
DTSTAMP:20260429T030740
CREATED:20240326T205445Z
LAST-MODIFIED:20240326T205445Z
UID:3419-1713874500-1713877800@colleges.claremont.edu
SUMMARY:Clocks\, parking garages\, and the solvability of the quintic: a friendly introduction to monodromy (Edray Goins\, Pomona College)
DESCRIPTION:Imagine the hands on a clock.  For every complete the minute hand makes\, the seconds hand makes 60\, while the hour hand only goes one twelfth of the way.   We may think of the hour hand as generating a group such that when we “move” twelve times then we get back to where we started.  This is the elementary concept of a monodromy group. In this talk\, we give a gentle introduction to a historical mathematical concept which relates calculus\, linear algebra\, differential equations\, and group theory into one neat theory called “monodromy”.  We explore lots of real world applications\, including why it’s so easy to get lost in parking garages\, and present some open problems in the field.  We end the talk with a discussion of how this is all related to solving polynomial equations\, such as Abel’s famous theorem on the insolubility of the quintic by radicals.
URL:https://colleges.claremont.edu/ccms/event/clocks-parking-garages-and-the-solvability-of-the-quintic-a-friendly-introduction-to-monodromy-edray-goins-pomona-college/
LOCATION:Estella 2099
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20240416T121500
DTEND;TZID=America/Los_Angeles:20240416T131000
DTSTAMP:20260429T030740
CREATED:20240324T220030Z
LAST-MODIFIED:20240326T015954Z
UID:3416-1713269700-1713273000@colleges.claremont.edu
SUMMARY:Primitive elements in number fields and Diophantine avoidance (Lenny Fukshansky\, CMC)
DESCRIPTION:The famous primitive element theorem states that every number field K is of the form Q(a) for some element a in K\, called a primitive element. In fact\, it is clear from the proof of this theorem that not only there are infinitely many such primitive elements in K\, but in fact most elements in K are primitive. This observation raises the question about finding a primitive element of small “size”\, where the standard way of measuring size is with the use of a height function. We discuss some conjectures and known results in this direction\, as well as some of our recent work on a variation of this problem which includes some additional avoidance conditions. Joint work with Sehun Jeong (CGU).
URL:https://colleges.claremont.edu/ccms/event/primitive-elements-in-number-fields-and-diophantine-avoidance-lenny-fukshansky-cmc/
LOCATION:Estella 2099
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20240409T121500
DTEND;TZID=America/Los_Angeles:20240409T131000
DTSTAMP:20260429T030740
CREATED:20240328T182316Z
LAST-MODIFIED:20240330T202911Z
UID:3421-1712664900-1712668200@colleges.claremont.edu
SUMMARY:Building TOWARD Geometry: Truncated Octahedra work as Rhombic Dodecahedra (Peter Kagey\, HMC)
DESCRIPTION:In late March\, students\, staff\, and faculty were invited to help collaboratively build a large-scale geometric sculpture on the campus of Harvey Mudd College\, demonstrating a relationship between truncated octahedra and rhombic dodecahedra\, which are two examples of space-filling polyhedra. I’ll talk about the process of designing and building the sculpture\, some geometry and combinatorics underlying the construction\, and some discoveries we made along the way.
URL:https://colleges.claremont.edu/ccms/event/antc-talk-peter-kagey-hmc-2/
LOCATION:Estella 2099
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20240402T121500
DTEND;TZID=America/Los_Angeles:20240402T131000
DTSTAMP:20260429T030740
CREATED:20231024T210058Z
LAST-MODIFIED:20240326T205224Z
UID:3301-1712060100-1712063400@colleges.claremont.edu
SUMMARY:Well-rounded lattices and security: what we (don't) know (Camilla Hollanti\, Aalto University\, Finland)
DESCRIPTION:I will give a brief introduction to well-rounded lattices and to their utility in wireless communications and post-quantum security. We will see how the lattice theta series naturally arises in these contexts and discuss its connections to well-rounded lattices. The talk is based on joint work with Laia Amoros\, Amaro Barreal\, Taoufiq Damir\, Oliver Gnilke\, David Karpuk\, Alex Karrila\, Niklas Miller\, and Ha Tran.
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-camilla-hollanti-aalto-university-finland/
LOCATION:Estella 2099
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20240326T121500
DTEND;TZID=America/Los_Angeles:20240326T131000
DTSTAMP:20260429T030740
CREATED:20231215T050545Z
LAST-MODIFIED:20240312T172417Z
UID:3331-1711455300-1711458600@colleges.claremont.edu
SUMMARY:Sublattices and subrings of Z^n and random finite abelian groups (Nathan Kaplan\, UC Irvine)
DESCRIPTION:How many sublattices of Zn have index at most X?  If we choose such a lattice L at random\, what is the probability that Zn/L is cyclic?  What is the probability that its order is odd?  Now let R be a random subring of Zn.  What is the probability that Zn/R is cyclic?  We will see how these questions fit into the study of random groups in number theory and combinatorics.  We will discuss connections to Cohen-Lenstra heuristics for class groups of number fields\, sandpile groups of random graphs\, and cokernels of random matrices over the integers.
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-nathan-kaplan-uc-irvine/
LOCATION:Estella 2099
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20240319T121500
DTEND;TZID=America/Los_Angeles:20240319T131000
DTSTAMP:20260429T030740
CREATED:20231025T032921Z
LAST-MODIFIED:20240206T000905Z
UID:3302-1710850500-1710853800@colleges.claremont.edu
SUMMARY:Almost-prime times in horospherical flows (Taylor McAdam\, Pomona)
DESCRIPTION:There is a rich connection between homogeneous dynamics and number theory.  Often in such applications it is desirable for dynamical results to be effective (i.e. the rates of convergence for dynamical phenomena are known).  In the first part of this talk\, I will provide the necessary background and relevant history to state an effective equidistribution result for horospherical flows on the space of unimodular lattices in R^n.  I will then describe an application to studying the distribution of almost-prime times (integer times having fewer than a fixed number of prime factors) in horospherical orbits and discuss connections of this work to Sarnak’s Mobius disjointness conjecture.  In the second part of the talk I will describe some of the ingredients and key steps that go into proving these results. If time allows\, I will conclude by discussing recent results and ongoing work with M. Luethi that strengthens and generalizes this work.
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-taylor-mcadam-pomona/
LOCATION:Estella 2099
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20240305T121500
DTEND;TZID=America/Los_Angeles:20240305T131000
DTSTAMP:20260429T030740
CREATED:20240206T040319Z
LAST-MODIFIED:20240206T040319Z
UID:3376-1709640900-1709644200@colleges.claremont.edu
SUMMARY:Homological mirror symmetry\, curve counting\, and a classical example: 27 lines on a nonsingular cubic surface (Reggie Anderson\, CMC)
DESCRIPTION:Though mirror symmetry requires much technical background\, it gained traction in the mathematical community when physicists Candelas-de la Ossa-Green-Parkes discovered enumerative invariants counting the number of rational degree d curves inside of certain space called a “quintic threefold.” This answered longstanding problems in enumerative geometry from antiquity. In particular\, the number of rational degree d=1 curves inside of the space counts the number of lines. We will review a simpler\, classical example: any nonsingular cubic surface contains exactly 27 lines.
URL:https://colleges.claremont.edu/ccms/event/homological-mirror-symmetry-curve-counting-and-a-classical-example-27-lines-on-a-nonsingular-cubic-surface-reggie-anderson-cmc/
LOCATION:Estella 2099
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20240227T121500
DTEND;TZID=America/Los_Angeles:20240227T131000
DTSTAMP:20260429T030740
CREATED:20240126T230120Z
LAST-MODIFIED:20240221T014138Z
UID:3354-1709036100-1709039400@colleges.claremont.edu
SUMMARY:The restricted variable Kakeya problem (Pete Clark\, University of Georgia)
DESCRIPTION:For a finite field F_q\, a subset of F_q^N is a Kakeya set if it contains a line in every direction (i.e.\, a coset of every one-dimensional linear subspace).  The finite field Kakeya problem is to determine the minimal size K(N\,q) of a Kakeya set in F_q^N.  This problem was posed by Wolff in 1999 as an analogue to the Kakeya problem in Euclidean N-space\, which was (and still is) one of the major open problems in harmonic analysis.  It caused quite a stir in 2008 when Zeev Dvir showed that for each fixed N\, as q -> oo\, K(N\,q) is bounded below by a constant times q^N: the Euclidean analogue of this result is not only proved but known to be false.\n\nBut what about the constant?  In 2009 Dvir-Kopparty-Saraf-Sudan gave a lower bound on K(N\,q) that was within a factor of 2 of an upper bound due to Dvir-Thas.  (I will briefly mention recent work of Bukh-Chao giving a decisive further improvement\, but that is not the focus of the talk.) The key to this improved lower bound is a multiplicity enhancement of a 1922 result of Ore. In this talk I want to give my own exposition of this work together with a mild generalization: if X is a subset of F_q^N \ {0}\, then an X-Kakeya set is a subset that contains a translate of the line generated by x for all x in X.  Putting K_X(N\,q) to be the minimal size of an X-Kakeya set in F_q^N\, I will give a lower bound on K_X(N\,q) that recovers the DKSS bound when X = F_q^N \ {0}.  This is similar in spirit to  “statistical Kakeya” results of Dvir and DKSS but not overlapping much; in fact\, I will give a statistical generalization of my result as well.
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-pete-clark-university-of-georgia/
LOCATION:Estella 2099
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20240220T121500
DTEND;TZID=America/Los_Angeles:20240220T131000
DTSTAMP:20260429T030740
CREATED:20231127T045722Z
LAST-MODIFIED:20240219T164238Z
UID:3328-1708431300-1708434600@colleges.claremont.edu
SUMMARY:Point-counting and topology of algebraic varieties (Siddarth Kannan\, UCLA)
DESCRIPTION:A projective algebraic variety X is the zero locus of a collection of homogeneous polynomials\, in projective space. When the polynomials have integer coefficients\, we can think of the k-valued points X(k) of the variety\, for any field k. Now suppose we have two different fields k and k’. How does the behavior of X(k) inform the behavior of X(k’)? It turns out that this is a rich line of inquiry. I will present a particularly pleasing example which relates the topology of the complex-valued points of X with the number of points it has over finite fields.
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-siddarth-kannan-ucla/
LOCATION:Estella 2099
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20240213T121500
DTEND;TZID=America/Los_Angeles:20240213T131000
DTSTAMP:20260429T030740
CREATED:20240116T192503Z
LAST-MODIFIED:20240116T202510Z
UID:3335-1707826500-1707829800@colleges.claremont.edu
SUMMARY:Quiver categorification of quandle invariants (Sam Nelson\, CMC)
DESCRIPTION:Quiver structures are naturally associated to subsets of the endomorphism sets of quandles and other knot-coloring structures\, providing a natural form of categorification of homset invariants and their enhancements. In this talk we will survey recent work in this area.
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-sam-nelson-cmc-3/
LOCATION:Estella 2099
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20240123T121500
DTEND;TZID=America/Los_Angeles:20240123T131000
DTSTAMP:20260429T030740
CREATED:20231020T203433Z
LAST-MODIFIED:20240117T005624Z
UID:3294-1706012100-1706015400@colleges.claremont.edu
SUMMARY:Using quantum statistical mechanical systems to study real quadratic fields (Jane Panangaden\, Pitzer College)
DESCRIPTION:The original Bost-Connes system was constructed in 1990 and is a QSM system with deep connections to the field of rationals. In particular\, its partition function is the Riemann-zeta function and its ground states evaluated on certain arithmetic objects yield generators of the maximal Abelian extension of the rationals. In this talk we describe the construction of a related QSM system adapted to the study of real quadratic fields\, called the Boundary GL2 System. We describe its thermal properties and show how these relate to class field theory of real quadratic fields. These results are joint work with Matilde Marcolli.
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-jane-panangaden-pitzer-college/
LOCATION:Estella 2099
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20231205T121500
DTEND;TZID=America/Los_Angeles:20231205T131000
DTSTAMP:20260429T030740
CREATED:20230926T180257Z
LAST-MODIFIED:20231130T000041Z
UID:3260-1701778500-1701781800@colleges.claremont.edu
SUMMARY:Skein algebra of a punctured surface (Helen Wong\, CMC)
DESCRIPTION:The Kauffman bracket skein algebra of a surface is at once related to quantum topology and to hyperbolic geometry. In this talk\, we consider a generalization of the skein algebra due to Roger and Yang for surfaces with punctures. In joint work with Han-Bom Moon\, we show that the generalized skein algebra is a quantization of Penner’s decorated Teichmuller space\, which consists of complete metrics of the surface with extra decoration at the punctures. Interestingly\, our proof relies on a connection between the skein algebra and the cluster algebras of tagged arcs due to Fomin\, Shapiro\, and Thurston.
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-helen-wong-cmc-2/
LOCATION:Roberts North 102\, CMC
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20231128T121500
DTEND;TZID=America/Los_Angeles:20231128T131000
DTSTAMP:20260429T030740
CREATED:20231009T153250Z
LAST-MODIFIED:20231121T192204Z
UID:3281-1701173700-1701177000@colleges.claremont.edu
SUMMARY:What can chicken nuggets tell us about symmetric functions\, positive polynomials\, random norms\, and AF algebras? (Stephan Garcia\, Pomona)
DESCRIPTION: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 symmetric functions\, trace polynomials\, and the statistical properties of certain AF C$^*$-algebras.
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-stephan-garcia-pomona/
LOCATION:Roberts North 102\, CMC
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20231121T121500
DTEND;TZID=America/Los_Angeles:20231121T131000
DTSTAMP:20260429T030740
CREATED:20231009T193529Z
LAST-MODIFIED:20231119T201433Z
UID:3282-1700568900-1700572200@colleges.claremont.edu
SUMMARY:On the Cox ring of a weighted projective plane blown-up at a point (Javier Gonzalez Anaya\, HMC)
DESCRIPTION: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\, known as blow-ups of weighted projective planes (WPP). Through the lens of toric geometry\, a WPP is characterized by a rational plane triangle. This allows us to reinterpret the problem combinatorially and show that the solution often emerges from a parameter space of such triangles. This is joint work with José Luis González and Kalle Karu.
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-javier-gonzalez-anaya-hmc/
LOCATION:Roberts North 102\, CMC
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20231114T121500
DTEND;TZID=America/Los_Angeles:20231114T131000
DTSTAMP:20260429T030740
CREATED:20230908T055625Z
LAST-MODIFIED:20231109T070158Z
UID:3177-1699964100-1699967400@colleges.claremont.edu
SUMMARY:f^*-vectors of lattice polytopes (Max Hlavacek\, Pomona College)
DESCRIPTION: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\, the f^* -vector of P coincides with the f-vector (counting faces of every dimension) of its unimodular triangulations (if they exist). We give several inequalities that hold among the coefficients of f^*-vectors of polytopes. These inequalities resemble striking similarities with existing inequalities for the coefficients of f-vectors of simplicial polytopes. Even though f^* -vectors of polytopes are not always unimodal\, we describe several families of polytopes that carry the unimodality property.
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-max-hlavacek-pomona-college/
LOCATION:Roberts North 102\, CMC
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20231107T121500
DTEND;TZID=America/Los_Angeles:20231107T131000
DTSTAMP:20260429T030740
CREATED:20230908T055420Z
LAST-MODIFIED:20231024T041512Z
UID:3176-1699359300-1699362600@colleges.claremont.edu
SUMMARY:Frobenius coin-exchange generating functions (Matthias Beck\, San Francisco State University)
DESCRIPTION:We study variants of the Frobenius coin-exchange problem: Given n positive relatively prime parameters\, what is the largest integer that cannot be represented as a nonnegative integral linear combination of the given integers? This problem and its siblings can be understood through generating functions with 0/1 coefficients according to whether or not an integer is representable. In the 2-parameter case\, this generating function has an elegant closed form\, from which many corollaries follow\, including a formula for the Frobenius problem. We establish a similar closed form for the generating function indicating all integers with exactly k representations\, with similar wide-ranging corollaries. This is joint work with Leonardo Bardomero.
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-matthias-beck-san-francisco-state-university/
LOCATION:Roberts North 102\, CMC
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20231031T121500
DTEND;TZID=America/Los_Angeles:20231031T131000
DTSTAMP:20260429T030740
CREATED:20230921T041133Z
LAST-MODIFIED:20231013T160601Z
UID:3248-1698754500-1698757800@colleges.claremont.edu
SUMMARY:On the spectra of syntactic structures (Isabella Senturia\, Yale University)
DESCRIPTION:We explore the application of spectral graph theory to the problem of characterizing linguistically-significant classes of tree structures. We focus on various classes of syntactically-defined tree graphs\, and show that the spectral properties of different matrix representations of these classes of trees provide insight into the linguistic properties that characterize these classes. More generally\, our goal is to provide another route to understanding the mathematical structure of natural language\, one that does not come from extensive definitions and rules defined via linguistic extrapolation\, but instead is extracted directly from computation on the syntactically-defined graphical structures.
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-via-zoom-isabella-senturia-yale-university/
LOCATION:On Zoom
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20231024T121500
DTEND;TZID=America/Los_Angeles:20231024T131000
DTSTAMP:20260429T030740
CREATED:20231003T045008Z
LAST-MODIFIED:20231003T234122Z
UID:3269-1698149700-1698153000@colleges.claremont.edu
SUMMARY:Deep hole lattices and isogenies of elliptic curves (Lenny Fukshansky\, CMC)
DESCRIPTION:For a lattice L in the plane\, we define the affiliated deep hole lattice H(L) to be spanned by a shortest vector of L and the furthest removed vector from the lattice contained in the triangle with sides corresponding to the shortest basis vectors. We study the geometric and arithmetic properties of deep hole lattices\, which turn out to be quite interesting. In particular\, we construct sequences of deep hole lattices corresponding to elliptic curves over a fixed number field. In the case of CM elliptic curves\, we prove that all elliptic curves generated by this sequence are isogenous to each other and produce bounds on the degree of isogeny. Finally\, we produce a counting estimate for the planar lattices with a prescribed deep hole lattice. Joint work with Pavel Guerzhoy and Tanis Nielsen.
URL:https://colleges.claremont.edu/ccms/event/deep-hole-lattices-and-isogenies-of-elliptic-curves-lenny-fukshansky-cmc/
LOCATION:Roberts North 102\, CMC
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20231003T121500
DTEND;TZID=America/Los_Angeles:20231003T131000
DTSTAMP:20260429T030740
CREATED:20230901T053808Z
LAST-MODIFIED:20230901T053808Z
UID:3170-1696335300-1696338600@colleges.claremont.edu
SUMMARY:Cellular resolutions of the diagonal and exceptional collections for toric D-M stacks (Reginald Anderson\, CMC)
DESCRIPTION:Beilinson gave a resolution of the diagonal for complex projective space\, which gives a strong\, full exceptional collection of line bundles as a generating set for the derived category of coherent sheaves. Bayer-Popescu-Sturmfels generalized Beilinson’s resolution of the diagonal by giving a cellular resolution of the diagonal for a proper subclass of smooth toric varieties which they called “unimodular.” In joint work with Gabe Kerr\, we extended this resolution of the diagonal to smooth projective toric varieties by showing that the cokernel of Bayer-Popescu-Sturmfels’ resolution is torsion with respect to the irrelevant ideal. In this talk\, we show that Bayer-Popescu-Sturmfels’ resolution yields a strong\, full\, exceptional collection of line bundles for unimodular projective toric surfaces\, and that our extended resolution of the diagonal yields a strong\, full exceptional collection of line bundles for a smooth\, non-unimodular projective toric surface.
URL:https://colleges.claremont.edu/ccms/event/cellular-resolutions-of-the-diagonal-and-exceptional-collections-for-toric-d-m-stacks-reginald-anderson-cmc/
LOCATION:Roberts North 102\, CMC
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20230926T121500
DTEND;TZID=America/Los_Angeles:20230926T131000
DTSTAMP:20260429T030740
CREATED:20230828T163632Z
LAST-MODIFIED:20230828T211001Z
UID:3153-1695730500-1695733800@colleges.claremont.edu
SUMMARY:Chromatic numbers of abelian Cayley graphs (Michael Krebs\, Cal State LA)
DESCRIPTION:A classic problem in graph theory is to find the chromatic number of a given graph: that is\, to find the smallest number of colors needed to assign every vertex a color such that whenever two vertices are adjacent\, they receive different colors.  This problem has been studied for many families of graphs\, including cube-like graphs\, unit-distance graphs\, circulant graphs\, integer distance graphs\, Paley graphs\, unit-quadrance graphs\, etc.  All of those examples just listed can be regarded as “abelian Cayley graphs\,” that is\, Cayley graphs whose underlying group is abelian.  Our goal is to create a unified\, systematic approach for dealing with problems of this sort\, rather than attacking each individually with ad hoc methods.  Building upon the work of Heuberger\, we associate an integer matrix to each abelian Cayley graph.  In certain cases\, such as when the matrix is small enough\, we can more or less read the chromatic number directly from the entries of the matrix.  In this way we immediately recover both Payan’s theorem (that cubelike graphs cannot have chromatic number 4) as well as Zhu’s theorem (which determines the chromatic number of six-valent integer distance graphs).  The proofs utilize only elementary group theory\, elementary graph theory\, elementary number theory\, and elementary linear algebra.  This is joint work with J. Cervantes.
URL:https://colleges.claremont.edu/ccms/event/antc-talk-michael-krebs-cal-state-la/
LOCATION:Roberts North 102\, CMC
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20230919T121500
DTEND;TZID=America/Los_Angeles:20230919T131000
DTSTAMP:20260429T030740
CREATED:20230830T200520Z
LAST-MODIFIED:20230830T203839Z
UID:3165-1695125700-1695129000@colleges.claremont.edu
SUMMARY:Biquandle power brackets (Sam Nelson\, CMC)
DESCRIPTION:Biquandle brackets are skein invariants of biquandle-colored knots\, with skein coefficients that are functions of the colors at a crossing. Biquandle power brackets take this idea a step further with state component values that also depend on biquandle colors. This is joint work with Neslihan Gügümcü (IYTE).
URL:https://colleges.claremont.edu/ccms/event/antc-seminar-sam-nelson-cmc-2/
LOCATION:Roberts North 102\, CMC
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20230912T121500
DTEND;TZID=America/Los_Angeles:20230912T131000
DTSTAMP:20260429T030740
CREATED:20230824T161426Z
LAST-MODIFIED:20230824T161426Z
UID:3146-1694520900-1694524200@colleges.claremont.edu
SUMMARY:Numerical semigroups\, minimal presentations\, and posets (Chris O'Neill\, SDSU)
DESCRIPTION:A numerical semigroup is a subset S of the natural numbers that is closed under addition.  One of the primary attributes of interest in commutative algebra are the relations (or trades) between the generators of S; any particular choice of minimal trades is called a minimal presentation of S (this is equivalent to choosing a minimal binomial generating set for the defining toric ideal of S).  In this talk\, we present a method of constructing a minimal presentation of S from a portion of its divisibility poset.  Time permitting\, we will explore connections to polyhedral geometry.\n\nNo familiarity with numerical semigroups or toric ideals will be assumed for this talk.
URL:https://colleges.claremont.edu/ccms/event/numerical-semigroups-minimal-presentations-and-posets-chris-oneill-sdsu/
LOCATION:Roberts North 102\, CMC
CATEGORIES:Algebra / Number Theory / Combinatorics Seminar
END:VEVENT
END:VCALENDAR