arXiv subjects
Publications and source records attributed to Nilanjan Bag.
This paper is devoted to finding moments of double exponential sums with monomials over arbitrary sets and intervals in finite fields. The study of such sums dates back to the work of Heath-Brown, who studied such sums in a work on least square-free numbers in an arithmetic progression.
In this paper, we study the distribution of difference of multiplicative and additive characters modulo $p$ at consecutive polynomial values. More precisely, for an interval $I$ over finite field and $0<m<1$, we investigate the following sums \begin{align*} \sum_{n\in I}|\psi(F(n))-\psi(F(n+1))|^{2m} \quad \text{and} \quad \sum_{n\in I}|\chi(F(n))-\chi(F(n+1))|^{2m}, \end{align*} where $\psi$ is a non-trivial additive character and $\chi$ is a non-trivial multiplicative character modulo $p$, under suitable conditions on $\chi$ and $F$. As a consequence, we derive a formula for the first moment by specializing to $m=1/2$.
Let $f$ be a real polynomial with irrational leading co-efficient. In this article, we derive distribution of $f(n)$ modulo one for all $n$ with at least three divisors and also we study distribution of $f(n)$ for all square-free $n$ with at least two prime factors. We study exponential sums when weighted by divisor functions and exponential sums over square free numbers. In particular, we are interested in evaluating \begin{align*} \sum_{n\leq N}τ(n)e\left(f(n)\right) ~\text{and}~\sum_{n\leq N}μ^2(n)e\left(f(n)\right), \end{align*} for some polynomial $f$, where $τ$ is the divisor function and $μ$ is the Möbius function. We get non-trivial estimates when the leading co-efficient $α$ of $f$ belongs to the minor arc.
The main purpose of this article is to study higher order moments of Kummer sums weighted by $L$-functions using estimates for character sums and analytic methods. The results of this article complement a conjecture of Zhang Wenpeng (2002). Also the results in this article give analogous results of Kummer's conjecture (1846).
In this paper, we develop a method of evaluating general exponential sums with rational amplitude functions for multiple variables which complements works by T. Cochrane and Z. Zheng on the single variable case. As an application, for $n\geq 2$, a fixed natural number, we obtain an asymptotic formula for the (weighted) number of solutions of quadratic congruences of the form $x_1^2+x_2^2+...+x_n^2\equiv x_{n+1}^2\bmod{p^m}$ in small boxes, thus establishing an equidistribution result for these solutions.
In this article, we prove an asymptotic formula for the fourth power mean of a general $s$-dimensional hyper-Kloosterman sum. We find the number of solutions of certain congruence equations mod $p$ which play an integral part to prove our main result. We use estimates for character sums and analytic methods to prove our theorem.
We use some elementary arguments to obtain a new bound on bilinear sums with weighted Kloosterman sums which complements those recently obtained by E. Kowalski, P. Michel and W. Sawin (2020).
The main purpose of this article is to study higher power mean values of generalized quadratic Gauss sums using estimates for character sums, analytic method and algebraic geometric methods. In this article, we prove two conjectures which were proposed in \cite{BLZ}.
In this paper we have estimated one multi-variable character sum \begin{align*} \sum_{a=2}^{p-2}\sum_{b=1}^{p-1}\sum_{c=2}^{p-2}\sum_{d=1}^{p-1}\left(\frac{a^2-b^2}{p}\right)\left(\frac{b^2-1}{p}\right) \left(\frac{c^2-d^2}{p}\right)\left(\frac{d^2-1}{p}\right)\left(\frac{a^2c^2-1}{p}\right), \end{align*} for odd prime $p$. With the help of our estimate of the above character sum, we have studied the tenth power mean value of generalized quadratic Gauss sums using estimates for character sums and analytic methods.
The main purpose of this paper is to study higher order moments of the generalized quadratic Gauss sums weighted by $L$-functions using estimates for character sums and analytic methods. We find asymptotic formulas for three character sums which arise naturally in the study of higher order moments of the generalized quadratic Gauss sums. We then use these character sum estimates to find asymptotic formulas for the $\nth{6}$ and $\nth{8}$ order moments of the generalized quadratic Gauss sums weighted by $L$-functions. Our asymptotic formulas satisfy a conjecture of Wenpeng Zhang.