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 e-mail 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).
There will be a poster session in the lower atrium of East Hall.
Dinner will be at Madras Masala at 6:30pm.
Speakers:
9-10: Drew Armstrong (University of Miami)
10:30-11:30 Rebecca Patrias (LaCIM)
2:00-3:00 Nathan Williams (UT Dallas)
3:30-4:30 Alexander Barvinok (U Michigan)
4:30-6 Poster session
6:30-? Dinner at Madras Masala
Schedule:
Coffee and pastries 8-9am
Drew Armstrong (University of Miami) 9:00-10:00am Title:
The Waldspurger TransformAbstract:
I will describe work with my graduate student James
McKeown. For any nXn "sum-symmetric" matrix M (in which the ith row sum
equals the ith column sum) we define an (n-1)X(n-1) 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) 10:30am-11:30am
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) 2:00-3:00pm
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) 3:30-4:30pm
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 off-diagonal entries in the
same row can be approximated in quasi-polynomial time. The same result holds
for multi-dimensional 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: 4:30-6:00pm
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Lunch: There are numerous lunch options within walking distance.
--------------------------------------------------------------------------------------------------------------------------------------------- Dinner: 6:30pm
At Madras Masala
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Getting to Ann Arbor:
Parking:
Childcare: Parents attending the conference and looking for childcare may find care.com a useful reference.
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