Algecom Committee: Hal Schenck Alexander Yong David Speyer Uli Walther Saugata Basu Evgeny Mukhin Peter Tingley Chris Drupieski Date: March 24, 2018
Location: Department of Mathematics at University of Michigan
Local Organizers (questions related to Algecom 16): David Speyer speyer@umich.edu
Registration is free. To register, email the local organizer David Speyer at speyer@umich.edu.If you are interested in presenting at the poster session, please email David Speyer at speyer@umich.edu.
There is some NSF support (hotel, airfare/car rental) for graduate students to attend. Interested students should apply by sending to following information toDavid Speyer (speyer@umich.edu), by February 15, 2018:1. Name: 2. Organization: 3. Will you be attending dinner? 4. Brief summary of research interests: 5. Research advisor: 6: Are you interested in presenting at the poster fair? 7. Approximate expenses:
Funding decisions will be made by February 20, 2018.
A block of rooms has been reserved for attendees at the University Inn (https://universityinnannarbor.com/, 734.971.8000, stay@universityinnannarbor.com).
Please contact the hotel to make your reservations. This is 1.7 miles from the conference building. As well as being a pleasant walk, we will organize carpools from the hotel to the conference, and bus route four (to conference, [www.theride.org] to the hotel [www.theride.org]) runs every half hour.
Nearby parking is available in the Forest Parking structure (here is a map).
All talks will be in East Hall 1360.
There will be a poster session in the lower atrium of East Hall.
Dinner will be at Madras Masala at 6:30pm.
Speakers: 910: Drew Armstrong (University of Miami) 10:3011:30 Rebecca Patrias (LaCIM) 2:003:00 Nathan Williams (UT Dallas) 3:304:30 Alexander Barvinok (U Michigan) 4:306 Poster session 6:30? Dinner at Madras Masala
Schedule:
Coffee and pastries 89am
Drew Armstrong (University of Miami) 9:0010:00am Title: The Waldspurger TransformAbstract: I will describe work with my graduate student James
McKeown. For any nXn "sumsymmetric" matrix M (in which the ith row sum
equals the ith column sum) we define an (n1)X(n1) matrix WT(M), called
its "Waldspurger transform." When M is a permutation matrix,
this yields a combinatorial description of a 2005 result of Waldspurger,
which decomposes the positive root cone as a strange disjoint union of
relatively open cones indexed by partitions. When M is an alternating
sign matrix the Waldspurger transform WT(M)
describes an order ideal in the "tetrahedral poset." These ideas mostly
generalize to type B and provide some hope for a theory of "type B
alternating sign matrices."Rebecca Patrias (LaCIM) 10:30am11:30am
Title: Promotion on generalized oscillating tableaux and web rotation
Abstract: We introduce the notion of a generalized oscillating tableau and define a promotion operation on such tableaux that generalizes the classical promotion operation on standard Young tableaux. As our main application, we show that this promotion corresponds to rotation of the irreducible $A_2$webs of G. Kuperberg.
Nathan Williams (UT Dallas) 2:003:00pm
Title: Fixed Points of Parking Functions
Abstract: We define an action of words in [m]^n on R^m to give a new characterization of parking functions. We use this viewpoint to give a simple definition of Gorsky, Mazin, and Vazirani's zeta map when m and n are coprime, and prove it is invertible. A specialization recovers Loehr and Warrington's sweep map on rational Dyck paths. This is joint work with Jon McCammond and Hugh Thomas.
Alexander Barvinok (U Michigan) 3:304:30pm
Title: Computing permanents of diagonally dominant matrices and tensors
Abstract: The permanent of an nxn times complex matrix in which the absolute value of each diagonal entry exceeds the sum of offdiagonal entries in the same row can be approximated in quasipolynomial time. The same result holds for multidimensional permanents of tensors. This is an illustration of the general principle: one can efficiently compute (approximate) a combinatorially defined polynomial in a complex domain provided the polynomial has no zeros in a slightly larger domain. As a corollary, we show how to count perfect matchings in a hypergraph, weighted by their Hamming distance to a given perfect matching.
Poster session and informal discussions: 4:306:00pm

Lunch: There are numerous lunch options within walking distance.
 Dinner: 6:30pm
At Madras Masala

Getting to Ann Arbor:
Parking:
Childcare: Parents attending the conference and looking for childcare may find care.com a useful reference.

