supported by the National Natural Science Foundation of China (Nos. 10171060, 10171076,10471104).
Let p denote a prime and P2 denote an almost prime with at most two prime factors. The author proves that for sufficiently large x,∑p≤x p+2=P2 1〉1.13Cx/log^2x,where the constant 1.13 constitutes an improvement of ...
Supported by the National Natural Science Foundation of China(10171076);Supported by the Scientific and Technical Committee Foundation of Shanghai(03JC14027)
Under certain condition, the inequality |λ_1p_1~2+λ_2p_2~2+λ_3p_3~2+λ_4p_4~2+μ_12^(x1)+…+μ_s2^(xs)+γ|<ηhas infinitely many solutions in primes p_1,p_2,p_3,p_4 and positive integers x_1,…,x_s.
Supported by the National Natural Science Foundation of China(10171076);Supported by the Scientific and Technical Committee Foundation of Shanghai(03JC14027)
To obtain a better Vinogradov's bound, assistant function with two or three zeros and all Dirichlet's characters has been evaluated. Assistant function g(X1,X2,X3,X4)with four zeros and all nonprincipal characters but...