From stacky wiki

Contact Information

Name: Anton Geraschenko
Phone: 617 275 1573 (cell)
Home: 2061 Ashton Ave, Menlo Park, CA 94025

Research Interests

Algebraic geometry, algebraic stacks, moduli, algebraic groups, representation theory.


Harry Bateman Research Instructor, Caltech, September 2011-2012.


  • University of California, Berkeley, California USA

Ph.D.May 2011, Dissertation Topic: "Toric Stacks", Adviser: Vera Serganova

  • Brandeis University, Waltham, Massachusetts USA

B.A. May 2004, Summa Cum Laude Physics and Mathematics with Highest Honors

Honors and Awards

  • National Science Foundation Graduate Research Fellowship, 2005-2008
  • Arnold Shapiro Prize in Mathematics, 2004


A "bottom up" characterization of smooth Deligne-Mumford stacks with Matthew Satriano. arXiv:1503.05478 IMRN September 2016
There is no degree map for 0-cycles on Artin stacks with Dan Edidin and Matthew Satriano. arXiv:1208.3239 Transformation Groups June 2013
Formal GAGA for good moduli spaces with David Zureick-Brown. arXiv:1208.2882 Algebraic Geometry May 2015
Torus Quotients as Global Quotients by Finite Groups with Matthew Satriano. arXiv:1201.4807 JLMS 2015
Toric Stacks I: The Theory of Stacky Fans with Matthew Satriano. arXiv:1107.1906 Transactions of the AMS 2015
Toric Stacks II: Intrinsic Characterization of Toric Stacks with Matthew Satriano. arXiv:1107.1907 Transactions of the AMS 2015

Synergistic Activities

  • ""; (Fall 2009-Spring 2014) founder and benevolent dictator.

The Stack Overflow of professional mathematicians, MathOverflow has been responsible for many fruitful collaborations, and has helped mathematicians overcome technical obstructions in their research. For many, it has become an extension of how they do mathematics. At the same time, the site is extremely useful for developing mathematicians since it has become a repository for "professional secrets," insights revealed by experts which are for one reason or another difficult to communicate in other media. It is not unusual for an answer to a question to come from the founder of the field!

Notably, much of MathOverflow's traffic comes from small institutions where individual researchers are are alone in their field. Such mathematicians have told me that MathOverflow has made them happier and more productive. The site has also served an important social role for developing mathematicians since it allows them to freely interact with other mathematicians at all stages in their careers. In this way, the site has filled an important niche, allowing mathematicians to effectively network by doing mathematics together rather than "networking."

Though MathOverflow is a professional forum not targeted at the general public, several general-interest articles have been written about it (for example, a featured article of the Simons Foundation, another in the Atlantic, the San Jose Mercury, as well as posts on several mathematical blogs). In addition to administering, moderating, and participating in MathOverflow, I have done interviews for these articles because I believe it is important to promote mathematics as a whole. In the same spirit, I gave a brief presentation about the site at the 2011 Open Science Summit (slides).

I'm no longer benevolent dictator, but MathOverflow has been incorporated as a 501(c)(3) non-profit, and I continue to serve on the board.

  • Caltech Algebraic Geometry Seminar; (Fall 2011) co-organizer.
  • Toric Geometry Student Seminar; (Fall 2011) faculty sponsor/organizer.
  • Berkeley Student Representation Theory Seminar; (Fall 2006 -- Spring 2007) organizer.

Seminar Presentations

  • When is a variety a quotient of a smooth variety by a finite group?

BIRS workshop. Algebraic Stacks: Progress and Prospects. (03-26-2012) (video)
Emory Algebraic Geometry Seminar. (03-20-2012)
UCSD Algebraic Geometry Seminar. (10-26-2011)
Claremont Algebra, Number Theory and Combinatorics Seminar. (10-25-2011)
WAGS (poster session; my poster). (10-01-2011)
University of Michigan Postdoc Algebraic Geometry Seminar. (09-12-2011)
Rice University Algebraic Geometry Seminar. (08-30-2011)

  • Toric Stacks

USC Algebra Seminar. (02-07-2011)
UW Madison Algebraic Geometry Seminar. (01-21-2011)
Stanford Algebraic Geometry Seminar. (10-29-2010)
Geometry, Representation theory, And Some Physics (GRASP) Seminar, UC Berkeley. (Fall 2010)

  • Moduli of Representations of Unipotent Groups

UW Madison Number Theory Seminar. (01-20-2011)
Lie Groups, Lie Algebras and their Representations Workshop. (Fall 2010)
Geometry, Representation theory, And Some Physics (GRASP) Seminar, UC Berkeley. (Spring 2010)

  • Introduction to Toric Varieties I & II

Student Algebraic and Arithmetic Geometry Seminar. (Spring 2008)

  • EGA IV §11 and the Valuative Criterion for Flatness

Clay sponsored EGA seminar. (Summer 2008)

  • EGA I §§3--4 Products and Immersions of Schemes

UC Berkeley EGA seminar. (Summer 2008)

  • The Salamader Lemma

Many Cheerful Facts (UC Berkeley graduate student colloquium). (Fall 2007)

  • Introduction to D-modules

D-modules seminar at UC Berkeley. (Summer 2007)

  • An overview of $U_q(\mathfrak{g})$ I & II

Berkeley student representation theory seminar. (Fall 2006)

  • Category Theory

Many Cheerful Facts (UC Berkeley graduate student colloquium). (Spring 2006)

  • Bruhat-Tits spaces and the exponential map

Many Cheerful Facts (UC Berkeley graduate student colloquium). (Fall 2005)

  • Buckyballs, glass, and origami

Many Cheerful Facts (UC Berkeley graduate student colloquium). (Fall 2005)

Teaching Experience

Software Skills

Proficient in Sage, Python, and Bash.


Vera Serganova Department of Mathematics University of California Berkeley Berkeley, CA 794720-3840
Martin Olsson Department of Mathematics University of California Berkeley Berkeley, CA 94720-3840
Ravi Vakil Department of Mathematics Stanford University Stanford, CA 94305
Tom Graber Department of Mathematics 253-37 California Institute of Technology Pasadena, CA 91125