Associate Professor
Department of Mathematics
University of California, Santa Cruz
Office: McHenry 4128
Email: sdasgup2 (at) ucsc (dot) edu
Mailing address:
Department of Mathematics
1156 High Street
Santa Cruz, CA 95064
Course Webpages
Math 134, Introduction to Cryptography
Math 202, Graduate Algebra III
UCSC Algebra and Number Theory Seminar
Seminar Calendar
Bay Area Algebraic Number Theory and Arithmetic Geometry Day
Day 12, April 9, 2016, Berkeley 
Day 11, December 5, 2015, Santa Cruz 
Day 10, February 21, 2015, Stanford 
Day 9, November 15, 2014, Berkeley 
Day 8, April 26, 2014, Stanford 
Day 7, December 7, 2013, Santa Cruz 
Day 6, April 6, 2013, Berkeley 
Day 5, November 10, 2012, Santa Cruz 
Day 4, March 3, 2012, Stanford 
Day 3, October 22, 2011, Santa Cruz 
Day 2, April 2, 2011, Berkeley 
Day 1, November 6, 2010, Santa Cruz 
On the GrossStark Conjecture, (with Mahesh Kakde and Kevin Ventullo), preprint. 

Factorization of padic Rankin Lseries, Inventiones Mathematicae, to appear. 

Partial zeta values, Gross's tower of fields conjecture, and GrossStark units,
(with Michael Spiess), submitted. 

Integral Eisenstein cocycles on GL_n, II: Shintani's Method,
(with Pierre Charollois and Matthew Greenberg), Commentarii Mathematici Helvetici, 90 (2015), no. 2, 435477. 

The padic Lfunctions of Evil Eisenstein Series,
(with Joel Bellaiche), Compositio Mathematica, 151 (2015), no. 6, 9991040. 

Integral Eisenstein cocycles on GL_n, I: Sczech's cocycle and padic Lfunctions of totally real fields,
(with Pierre Charollois), Cambridge Journal of Mathematics, 2 (2014), no. 1, 4990. 

A Conjectural Product formula for BrumerStark units over Real Quadratic Fields,
Journal of Number Theory, 133 (2013), no. 3, 915925 (volume in memory of David Hayes). 

LInvariants and Shimura Curves,
(with Matthew Greenberg), Algebra and Number Theory, 6 (2012), no. 3, 455485. 

Hilbert Modular Forms and the GrossStark Conjecture,
(with Henri Darmon and Robert Pollack), Annals of Mathematics, 174 (2011), no. 1, 439484. 

A ShintaniType Formula for GrossStark Units over Function Fields,
(with Alison Miller), Journal of Mathematical Sciences, The University of Tokyo, 16 (2009), no. 3, 415440. 

Shintani Zeta Functions and GrossStark Units for Totally Real Fields,
Duke Mathematical Journal, 143 (2008), no. 2, 225279. 

Computations of Elliptic Units for Real Quadratic Fields,
Canadian Journal of Mathematics, 59 (2007), 553574. 

Elliptic Units for Real Quadratic Fields, (with Henri Darmon), Annals of Mathematics, 163 (2006), no. 1, 301345. 

StarkHeegner Points on Modular Jacobians,
Annales Scientifiques de l'École Normale Supérieure, 4e sér., 38 (2005), 427469. 

Transversals of Additive Latin Squares, (with Gyula Károlyi, Oriol
Serra, and Balázs Szegedy), Israel Journal of Mathematics, 126 (2001), 1728. 

A Presentation for the Unipotent Group over Rings
with Identity, (with Daniel Biss), Journal of Algebra, 237 (2001), no. 2, 691707. 

On the Size of Minimum Super Arrovian Domains,
SIAM Journal of Discrete Mathematics, 12 (1999), no. 4, 524534. 
padic Lfunctions and Euler systems: a tale in two trilogies,
(with Massimo Bertolini, Francesc Castella, Henri Darmon, Kartik Prasanna, and Victor Rotger), submitted to Durham conference Proceedings. 

Heegner Points and Sylvester's Conjecture, (with John Voight), Arithmetic Geometry, Clay Mathematics Proceedings, 8. American Mathematical Society, Providence, RI, 2009. 

The padic Upper Half Plane, (with Jeremy Teitelbaum), padic Geometry: Lectures from the 2007 Arizona Winter School, ed. David Savitt, Dinesh Thakur. University Lecture Series, 45. American Mathematical Society, Providence, RI, 2008. 

StarkHeegner Points and Special Values of Lseries, (with Massimo Bertolini and Henri Darmon), LFunctions and Galois Representations, ed. David Burns, Kevin Buzzard, Jan Nekovář. London Mathematical Society Lecture Note Series, 320. Cambridge University Press, Cambridge, 2007. 

Unités Elliptiques, Corps Quadratiques Réels,
et une Formule Limite de Kronecker, (avec Henri Darmon), Proceedings de la Troisième Conférence Internationale de Théorie des Nombres QuebecMaroc, Mai 2003, CasablancaMarrakech. Annales des sciences mathématiques du Québec, 28 (2005), no. 12, 7788. 
GrossStark Units, StarkHeegner Points, and Class Fields of
Real Quadratic Fields,
PhD. Thesis, University of CaliforniaBerkeley, May 2004. 

Stark's Conjectures, Senior honors thesis, Harvard University, April 1999. 
Talk 2: Trivial zeroes of padic Lfunctions
Talk 3: Factorization of padic Rankin Lfunctions
In 2008, I organized a conference with Frank Calegari, Bjorn Poonen, and Richard Taylor on
Modular Forms
and Arithmetic at UCBerkeley and MSRI (June 28Jul 2, 2008). During the conference
we honored Ken Ribet on his 60th birthday.
Here are the slides
from my talk at the conference.
Here is the
senior thesis of Kaloyan Slavov, which provides computational
evidence for the conjecture stated in my paper on Shintani zeta functions above.
Here are my
slides from Banff on this topic.
Here are my
slides from the UCLA conference on Iwasawa theory about Ribet's method.