Math 5810 ACSV course page, Fall 2025


Prof: Robin Pemantle, DRLB 4N22, pemantle@math.upenn.edu , Zoom 932 808 9909
Resource: Kaitian Jin, kaitian@sas.upenn.edu

Ed Discussion link

To join the course Ed Discussion site the first time



CURRENT TO-DO LIST

READING for April 23: Chapter 11. This is a condensation of a condensation of large parts of [ABG70]. It is difficult to take in. You might try Baryshnikov-Pemantle (2011) on my web page.

Resources:
de Loera and Sturmfels (2001): counting lattice points in polytopes
Atiyah, Bott and Garding (1970) : very long, very good paper, with foundational constructions for generalized Fourier transforms and deformations of cycles

Resources:
Baryshnikov et al. paper on hyperplane arrangement denominators in ACSV

Melczer et al. (2025): FPSAC paper on the new SageMath package for ACSV
   Link to the SageMath package itself (see FPSAC paper for links to instructions and documentation)

READING for April 14-16: Chapter 10. This is the first time we're having any nontrivial discussion of critical points where the variety is not smooth. The case in Chapter 10, namely nicely intersecting sheets, is reasonably well understood, so it's a good place to see how the topology works in advance of much harder cases. I hope to spend the second half of April on "cone points", which are the pinnacle of ACSV acheivement at this time (Chapter 11).

READING for April 2: Chapter 5. You might also want to look at Section 9.4.2.
UPCOMING READING for the week of April 7-9: Chapter 8 (effective computation).

For computational algebra, I recommend these sources as well:
Steve Melczer (Springer)
Invitation to Analytic Combinatorics in Several Variables
Cox, Little and O'Shea (Springer GTM)
Using Algebraic Geometry
Bernd Sturmfels (CBMS)
Solving Systems of Polynomial Equations

My plan is to start MON 3/31 with an explanation of the main result in Chapter 5 (Theorem 5.2: multivariate saddle point integrals in the quadratically nondegenerate case), then go through one or more two-dimensional quantum walk examples, then go back to the fancier result (Theorem 5.3) which is needed for quantum walks.

Papers on Quantum Walk:

   Barynshnikov-Bressler-Brady-Pemantle (2010): proves the relation between amplitude and curvature

   Bressler-Greenwood-Pemantle-Petkovsek (2010): Investigates QRW in 1 and 2 dimensions

   Bressler-Pemantle (2007): investigates 1-dimensional quantum walk via generating functions

READING for FEB 26 and March 17,19: Read through Chapter 7, referring to the Appendices when necessary.

I plan to postpone Chapter 5 until we need it and instead dive into Chapter 7, which discusses the general approach that sets up ACSV computations in terms of integrals over certain cycles. The cycles are chosen via Morse theory and then evaluated asymptotically via the techniques in Chapters 4 and 5. In class on FEB 24-26 mostly what we will get to is the background: the algebraic topology that forms a foundation (Appendix B, drawing on Appendix A which you probably already know) and Appendix C on intersection cycles and residue forms which you probably don't know. In class on March 17-19 (recall that I'm out of town next week, after which we have Spring Break), we will go through Chapter 7 more or less.

TO DO NOW: check whether you can do all the exercises in A.1 and A.2.1. I will assume yes, so let me know if not. Skim the rest of of Appendix A, feel you really don't know, so I can go over them. Ditto Appendix B. You don't need to go beyond this, since I'm assuming you don't know what's in Appendices C and D.

Maple worksheet for Nikita's no three in a row generating function
static version (pdf) of same worksheet



READING for Feb 10-12-17: For February 10 there's no specific reading, but you might want to skim Chapter 6. I will be spending the day on an informal introduction to multivariate domeains of convergence for power series and Laurent series. For February 12-17, read Chapter 4. We will spend February 12 on 4.1 and some part of 4.2.

Please let me know your preferences as to what to discuss among the following topics:
    Exercises 4.1 - 4.8
    Real life examples of Fourier-Laplace integrals
    Proofs of anything in particular in Chapter 4
    Any concepts in Chapter 6 (not proofs: this is just a first look)


READING for Feb 03: Chapter 3, concentrating on sections 3 and 4.

From last time: I posted Christol's paper surveying results and conjectures on diagonals of rational functions, D-finiteness and global boundedness.
I also posted Mark Ward's paper solving Wilf's problem on the generating function with the arctangent, under MATERIALS, below.

READING for Jan 27: Remainder of Chapter 2 - sections 3,4,5.

PLANNED DISCUSSION Jan 27: natural operations on ordinary generating functions; algebraic functions and the kernel method; exponential generating functions and their natural operations; D-finite functions.

PROBLEMS to discuss Jan 27:
Exercises 2.1, 2.2, 2.4, 25 from the textbook. During class we will make a plan for topics and problems to discuss from the remainder of Chapter 2.

READING for Jan 22:
Chapter 1 (mostly for interest, there's not much formal math there)
Sections 1 and 2 of Chapter 2

PROBLEMS to discuss Jan 22:
Asymptotics exercises posted below: if these don't seem too easy, it's a sign you should work them.
Asymptotics exercises from the textbook 1.2, 1.3, 1.4: these are classical examples -- worth knowing, but not straightforward.
Arctangent problem: work on this problem if you're curious about it. Over the course of the semester, you should choose some nontrivial problems to work on but you don't need to work on every one.



MATERIALS

Course Description

Book: "Analaytic Combinatorics in Several Variables", Pemantle, Wilson and Melczer (CUP, 2024).
  link to Cambridge University Press website for the book
  link to the ACSV project site where you can find a download link for the manuscript version of the book and other fun stuff

Book: "An Invitation to Analaytic Combinatorics in Several Variables", Melczer, Stephen (Springer, 2021).
  link to online manuscript version
  link to Springer website for purchase

Book: "Asymptotic Methods in Analysis", N. G. De Bruijn (North Holland 1948, 1961, 1970; reprinted by Dover in 1981)
  I don't have a link to an online copy but this gets you to the Math Library entry and I placed one of the copies on reserve

Book: "A Primer of Algebraic D-modules", S. C. Coutinho (London Mathematical Society Student Texts #33, Cambridge University Press 1995))
  I don't have a link to an online copy but this gets you to the Math Library entry

Paper: "Asymptotic Rational Approximation To Pi: Solution of an Unsolved Problem Posed By Herbert Wilf"
  Link to the published version


Handout on asymptotics




PROBLEMS

asymptotics exercises


branches of the arctangent



SOLUTIONS

Some numerics concerning the arctan problem
Maple worksheet version of the numerics