On a generalized Calabi-Yau equation
Dealing with the generalized Calabi-Yau equation proposed by Gromov on closed almost-Kähler manifolds, we extend to arbitrary dimension a non-existence result proved in complex dimension 2.
math.SG↗
arXiv subjects
Hongyu Wang
Publications and source records attributed to Hongyu Wang.
Exponential Sums, Cyclic Codes and Sequences: the Odd Characteristic Kasami Case
Let $q=p^n$ with $n=2m$ and $p$ be an odd prime. Let $0\leq k\leq n-1$ and $k\neq m$. In this paper we determine the value distribution of following exponential(character) sums \[\sum\limits_{x\in \bF_q}ζ_p^{\Tra_1^m (αx^{p^{m}+1})+\Tra_1^n(βx^{p^k+1})}\quad(α\in \bF_{p^m},β\in \bF_{q})\] and \[\sum\limits_{x\in \bF_q}ζ_p^{\Tra_1^m (αx^{p^{m}+1})+\Tra_1^n(βx^{p^k+1}+\ga x)}\quad(α\in \bF_{p^m},β,\ga\in \bF_{q})\] where $\Tra_1^n: \bF_q\ra \bF_p$ and $\Tra_1^m: \bF_{p^m}\ra\bF_p$ are the canonical trace mappings and $ζ_p=e^{\frac{2πi}{p}}$ is a primitive $p$-th root of unity. As applications: (1). We determine the weight distribution of the cyclic codes $\cC_1$ and $\cC_2$ over $\bF_{p^t}$ with parity-check polynomials $h_2(x)h_3(x)$ and $h_1(x)h_2(x)h_3(x)$ respectively where $t$ is a divisor of $d=\gcd(m,k)$, and $h_1(x)$, $h_2(x)$ and $h_3(x)$ are the minimal polynomials of $π^{-1}$, $π^{-(p^k+1)}$ and $π^{-(p^m+1)}$ over $\bF_{p^t}$ respectively for a primitive element $π$ of $\bF_q$. (2). We determine the correlation distribution among a family of m-sequences. This paper extends the results in \cite{Zen Li}.
cs.IT↗
Cyclic Codes and Sequences: the Generalized Kasami Case
Let $q=2^n$ with $n=2m$ . Let $1\leq k\leq n-1$ and $k\neq m$. In this paper we determine the value distribution of following exponential sums \[\sum\limits_{x\in \bF_q}(-1)^{\Tra_1^m (αx^{2^{m}+1})+\Tra_1^n(βx^{2^k+1})}\quad(α\in \bF_{2^m},β\in \bF_{q})\] and \[\sum\limits_{x\in \bF_q}(-1)^{\Tra_1^m (αx^{2^{m}+1})+\Tra_1^n(βx^{2^k+1}+\ga x)}\quad(α\in \bF_{2^m},β,\ga\in \bF_{q})\] where $\Tra_1^n: \bF_q\ra \bF_2$ and $\Tra_1^m: \bF_{p^m}\ra\bF_2$ are the canonical trace mappings. As applications: (1). We determine the weight distribution of the binary cyclic codes $\cC_1$ and $\cC_2$ with parity-check polynomials $h_2(x)h_3(x)$ and $h_1(x)h_2(x)h_3(x)$ respectively where $h_1(x)$, $h_2(x)$ and $h_3(x)$ are the minimal polynomials of $π^{-1}$, $π^{-(2^k+1)}$ and $π^{-(2^m+1)}$ over $\bF_{2}$ respectively for a primitive element $π$ of $\bF_q$. (2). We determine the correlation distribution among a family of m-sequences. This paper is the binary version of Luo, Tang and Wang\cite{Luo Tan} and extends the results in Kasami\cite{Kasa1}, Van der Vlugt\cite{Vand2} and Zeng, Liu and Hu\cite{Zen Liu}.
cs.IT↗
The Brillouin Instability of intense laser in relativistic plasmas
This paper studies the propagation of intense laser in plasmas in weak relativistic region($0.1<a_0^2<0.5$) using the quasi-periodic approximation. Effective Lorentz factor and density wave effects are calculated in detail. The relativistic correction on stimulated Brillouin instability is investigated in the rest parts. The coupled dispersion relations of Stimulated Brillouin Scattering(SBS) are obtained and investigated numerically.
physics.plasm-ph↗