Mathematics Building, Room 422
Columbia University
New York, NY 10027 
(212) 854-4304
       Fax: (212) 854-8962


Research Interests:  Number Theory curriculum vitae
Some Preprints: (pdf files)
An additive prime divisor function of Alladi and Erdős
A standard zero free region for Rankin-Selberg L-functions (with X. Li)

A converse theorem for double Dirichlet series and Shintani zeta functions
                                                   (with N. Diamantis)
On the determination of the Plancherel measure for Lebedev-Whittaker transforms on GL(n)
(with A. Kontorovich)
Fourier expansions of GL(2) newforms at various cusps
                                        (with J. Hundley and M. Lee)
Natural boundaries and the correct notion of integral moments of L-functions
                                                            (with A. Diaconu and P. Garrett)
Moments for L-functions for GL(r) x GL(r-1) (with A. Diaconu and P. Garrett)
A converse theorem for double Dirichlet series (with N. Diamantis)
Voronoi Formulas on GL(n) (with X. Li)
Second Moments of GL(2) L-Functions (with A. Diaconu)
Counting Congruence Subgroups (with A. Lubotzky and L. Pyber)
Multiple Dirichlet Series and Moments of Zeta and L-Functions
                                                 (with A. Diaconu and J. Hoffstein)
Modular Forms, Elliptic Curves, and the ABC Conjecture
The Gauss Class Number problem for Imaginary Quadratic Fields
The Elementary proof of the Prime Number Theorem,  An Historical Perspective 

Automorphic Representations and L-Functions for the General Linear Group, Volume 1
Automorphic Representations and L-Functions for the General Linear Group, Volume 2
Automorphic Forms and L-Functions for the Group GL(n,R) 
Blog with corrections of Errors in the above books
                    (Goldfeld Conference photos)

                    Joint COLUMBIA-CUNY-NYU Number Theory Seminar
                    Bretton Woods Workshop on Multiple Dirichlet Series(2005)    (Conference photos)
                    AAG key exchange
                    Edinburgh Workshop on Multiple Dirichlet Series(2008)
                    Decision Regarding World Record Musky Challenge
                    My Daughter's art work (including my portrait above)
                    Some Interesting Chemistry
                    Very accurate clock


  TR 11:40 - 12:55  Location: Room 520 Mathematics Building

RECOMMENDED (not required) Textbooks:

Multiplicative Number Theory,  Harold Davenport,  Springer-Verlag
A Course in Arithmetic,  Jean-Pierre Serre,  Springer-Verlag

TA:  Gerhardt Hinkle

Help Room (Math 406) Hours: 
Mondays 4-6pm  and Thursdays 2-3pm.

FINAL EXAM:  Tuesday, May 1 from 1:00-4:00 p.m. in Room 507 Math Building (40% of total grade for this class).

HOMEWORK:  (60% of total grade for this course) 

Homework #1 (due Tuesday, February 6):

Homework #2 (due Thursday, February 22):

Homework #3 (due Tuesday, March 20):

Homework #4  (due Thursday, April 19):