Number Theory Preprints
 Todd Cochrane


New Papers (2008-2010):
Exponential sums over subgroups of $\mathbb Z_p^*$, with Chris Pinner (2010),  pdf, dvi
Bounds on fewnomial exponential sums over $\mathbb Z_p^*$, with Chris Pinner (2010), pdf, dvi
Sum-product estimates applied to Waring's problem over finite fields, with J. Cipra, (2010),  pdf, dvi
Small values of Waring's number mod p, with C. Pinner, (2010), pdf, dvi
Small zeros of quadratic forms mod p^2, with Ali Hakami (2010), pdf, dvi
On the parity of k-th powers mod p, a generalization of a problem of Lehmer, with ... (2009)  pdf, dvi
Explicit bounds on monomial and binomial exponential sums, with C. Pinner, (2009) pdf, dvi
The congruence $x_1x_2=x_3x_4 \pmod m$ and mean values of character sums
, with S. Shi, (2009)  pdf, dvi
Decimations of $l$-sequences and permutations of even residues mod $p$, with J. Bourgain, J. Paulhus and C. Pinner,
         SIAM J. Discrete Math. 23 (2009), no. 2, 842-857. dvi, pdf
Waring's number mod $m$, with A. Alnaser, J. Number Theory 128 (2008), no. 9, 2582-2590. pdf, dvi
Sum-product estimates applied to Waring's problem mod $p$,  with C. Pinner,  Integers 8 (2008),  A46, 18pp. pdf, dvi



Monographs:  
I) Small Solutions of Congruences, Ph.D. Thesis, University of Michigan, 1984, 1-106.  (Advisor: D.J. Lewis)     pdf
II) Exponential Sums and the Distribution of Solutions of Congruences, Inst. of Math., Academia Sinica, Taipei, Taiwan (1994), 1-84  pdfdvi

Additive Combinatorics:
1) Sum-product estimates applied to Waring's problem mod $p$. Integers 8 (2008), A46, 18pp. pdf, dvi
2) Sum-product estimates applied to Waring's problem over finite fields, with J. Cipra, (2010),  pdf, dvi
3) Small values of Waring's number mod p, with C. Pinner, (2010), pdf, dvi

Distribution of Solutions of Congruences:
1) Small Solutions of Congruences, Ph.D. Thesis, University of Michigan, 1984,  Advisor: D.J. Lewis.     pdf
2) The distribution of solutions to equations over finite fields, Trans. Amer. Math. Soc. 293 (1986), no. 2  819-826.   pdf, dvi
3) Small solutions of congruences over algebraic number fields, Illinois J. Math. 31 (1987), no. 4, 618-625.   pdf, dvi
4) Small solutions of cubic congruences,  Proc. Amer. Math. Soc. 106 (1989), no. 2, 333-334.   pdf, dvi
5) Exponential Sums and the Distribution of Solutions of Congruences, Institute of Mathematics, Academia Sinica, Taipei, Taiwan (1994), 1-84, pdf, dvi

Exponential Sums over finite fields:
1)
Exponential Sums and the Distribution of Solutions of Congruences, Inst. of Math., Academia Sinica, Taipei, Taiwan (1994), 1-84  pdf,  dvi
2) Bounds on complete exponential sums, Analytic number theory, Vol. 1 (Allerton Park, IL, 1995), 211-224, Progr. Math., 138,
        Birkhauser Boston, Boston, MA, 1996. pdf, dvi
3) Bounds on exponential sums and the polynomial Waring problem mod $p$ with Chris Pinner and Jason Rosenhouse,  J. London Math. Soc. (2) 67 (2003),
        no. 2, 319-336.   pdf, dvi    
4) An improved Mordell type bound for exponential sums, with Chris Pinner,  Proc. Amer. Math. Soc. 133 (2005), no. 2, 313-320.   pdf, dvi
5) A further refinement of Mordell's bound on exponential sums, with Jeremy Coffelt and Chris Pinner,  Acta Arith. 116 (2005), no. 1, 35-41. pdf, dvi
6) Stepanov's method applied to binomial exponential sums, with Chris Pinner,  Q. J. Math. 54 (2003), no. 3, 243-255.  pdf, dvi
7) Using Stepanov's method for exponential sums involving rational functions, with Chris Pinner, J. Number Theory 116 (2006), no. 2, 270-292. pdf, dvi
8) A system of simultaneous congruences arising from trinomial exponential sums, with Jeremy Coffelt and Chris Pinner J. Theor. Nombres Bordeaux
        18 (2006), no. 1, 59-72, pdf, dvi
 
Exponential Sums modulo prime powers:
1) Pure and mixed exponential sums, with Zhiyong Zheng,  Acta Arith. 91 (1999), no. 3, 249-278. pdf, dvi
2) Exponential sums with rational function entries, Acta Arith. 95 (2000), no. 1, 67-95. pdf, dvi
3) On upper bounds of Chalk and Hua for exponential sums, with Z. Zheng, Proc. Amer. Math. Soc. 129, no. 9, (2001), 2505-2516. pdf, dvi
4)
Bounds for certain exponential sums, with Z. Zheng,  Asian J. Math. 4 (2000), no. 4, 757-773. pdf, dvi
5) Upper bounds on $n$-dimensional Kloosterman sums, with M-C Liu and Z. Zheng, J. Number Theory 106 (2004), no. 2, 259-274. pdf, dvi
6) Upper bounds on a two-term exponential sum, with Z. Zheng, Sci. China Ser. A 44 (2001), no. 8, 1003-1015. pdf, dvi
7) Exponential sums modulo prime powers, Acta Arith. 101 (2002), no. 2, 131-149. pdf, dvi
8) A survey on pure and mixed exponential sums modulo prime powers, with Z. Zheng,  Number theory for the millennium, I (Urbana, IL, 2000), 273-300, A K
        Peters, Natick,MA,
2002. dvi, pdf
9) Sparse polynomial exponential sums, with J. Rosenhouse and C. Pinner,  Acta Arith. 108 (2003), no. 1, 37-52. pdf, dvi


Multiplicative Character Sums:
1) An upper bound for character sums, (1987) preprint, pdf
1)
The congruence $x\sb 1x\sb 2\equiv x\sb 3x\sb 4\pmod p$, the equation $x\sb 1x\sb 2=x\sb 3x\sb 4$, and mean values of character sums, with A . Ayyad  and  Z. Zheng, J. Number Theory 59 (1996), no. 2, 398-413. pdf, dvi
2) High order moments of character sums, with Z. Zheng, Proc. Amer. Math. Soc. 126 no. 4 (1998), 951-956. pdf, dvi
3) On a problem of H. Cohn for character sums, with D. Garth and Z. Zhiyong,  J. Number Theory 81 (2000), 120-129. pdf, dvi
4) Upper bounds on character sums with rational function entries, with C.L. Liu and Z. Zheng, Acta Math. Sin. (Engl. Ser.) 19 (2003), no. 2, 327-338.
         pdfdvi


Quadratic Forms:
1) Small zeros of quadratic forms modulo p, J. Number Theory 33 no. 3 (1989), 286-292, pdf, dvi
2) Small zeros of quadratic forms modulo p, II,Proc. Illinois Number Theory Conference of 1989, Birkhauser, Boston (1990), 91-94. pdf, dvi
3) Small zeros of quadratic forms modulo p, III, J. Number Theory 37 no. 1 (1991), 92-99, pdf, dvi
4) Small zeros of quadratic congruences modulo pq, Mathematika 37 (1990), 261-272, pdf, dvi
5) Small zeros of quadratic congruences modulo pq, II, J. Number Theory 50 no. 2 (1995), 299-308. pdf, dvi
6) On representing the multiple of a number by a quadratic form, Acta Arith. 63 no. 3 (1993), 211-222, pdf, dvi
7) Small solutions of the congruence $a\sb 1x\sp 2\sb 1+a\sb 2x\sp 2\sb 2+a\sb 3x\sp 2\sb 3+a\sb 4x\sp 2\sb 4\equiv c\pmod p$, with Z. Zheng,
        Acta Math. Sinica (N.S.)
14 (1998), no. 2, 175-182. pdf, dvi
8) Small solutions of the Legendre equation, with P. Mitchell, J. Number Theory 70 no. 1 (1998), 62-66, pdf, dvi
9) Lattices in $\Bbb Z\sp 2$ and the congruence $xy+uv\equiv c\pmod m$, with A. Ayyad, Acta Arith. 132 (2008), no. 2, 127--133. pdf, dvi
10) The congruence $x\sb 1x\sb 2\equiv x\sb 3x\sb 4\pmod p$, the equation $x\sb 1x\sb 2=x\sb 3x\sb 4$, and mean values of character sums, with A . Ayyad  and  Z. Zheng, J. Number Theory 59 (1996), no. 2, 398-413. pdf, dvi
11) The congruence $x_1x_2=x_3x_4 \pmod m$ and mean values of character sums, with S. Shi, (2009)  pdf,  dvi

Trigonometric Sums:
1) On a trigonometric inequality of Vinogradov, J. Number Theory 26 no. 1 (1987), 9-16.  pdf, dvi
2) An asymptotic formula for a trigonometric inequality of Vinogradov, with J.C. Peral,  J. Number Theory 91 (2001), 1-19. pdf, dvi
3) Trigonometric approximation and uniform distribution modulo one, Proc. of the A.M.S. 103 no. 3 (1989), 695-702. pdf, dvi
Uniform Distribution:
1)
Trigonometric approximation and uniform distribution modulo one, Proc. of the A.M.S. 103 no. 3 (1989), 695-702. pdf, dvi
2) Decimations of $l$-sequences and permutations of even residues mod $p$, with J. Bourgain, J. Paulhus and C. Pinner,
         SIAM J. Discrete Math. 23 (2009), no. 2, 842-857. dvi, pdf
3) Distribution of $\lambda$-roots of composite moduli, with L. Xia and Z. Zheng, (2004) preprint, pdf, dvi
4) Distribution of primitive $\lambda$-roots of composite moduli II, with Z. Zheng, Chinese Annals of Math.-Series B, 27, no. 5. (2006), 549-552. pdf,dvi

Waring's Problem (mod p), (mod m) and over finite fields:
1) Bounds on exponential sums and the polynomial Waring problem mod $p$ with Chris Pinner and Jason Rosenhouse, 
         J. London Math. Soc. (2) 67 (2003), no. 2, 319-336.   pdf, dvi 
2) Heilbronn's conjecture on Waring's number (mod $p$), with J. Cipra and C. Pinner, J. Number Theory 125 (2007), no. 2, 289-297. pdf, dvi
3) Waring's number mod $m$, with A. Alnaser, J. Number Theory 128 (2008), no. 9, 2582-2590. pdf, dvi
4) Sum-product estimates applied to Waring's problem mod $p$. Integers 8 (2008), A46, 18pp. pdf, dvi
5) Sum-product estimates applied to Waring's problem over finite fields, with J. Cipra, (2010),  pdf, dvi
6) Small values of Waring's number mod p, with C. Pinner, (2010), pdf, dvi

Miscellaneous Number Theory:
1) Consecutive triples of sums of two squares, with R.E. Dressler, Archiv der Math. 49 (1987), 301-304, pdf, dvi
2) The diophantine equation f(x)=g(y), Proc. of the A.M.S. 109 no. 3 (1990), 573-577. pdf, dvi
3) Strong Riesz sets and polynomials, with R.E. Dressler, Colloquium Math. 58 (1989), 23-27. pdf, dvi
4) Covering congruences in higher dimensions, with G. Myerson, Rocky Mountain J. of Math. 26 no. 1 (1996), 77-81. pdf, dvi
5) Gaps between integers with the same prime factors, with R. Dressler, Math. Comp. 68 no. 225 (1999), 395-40. pdf, dvi