Speciality:
01.01.02 (Differential equations, dynamical systems, and optimal control)
Birth date:
18.05.1955
Keywords: differential inequalities; Green functions; elliptic functions; Chebyshev approximation; continued fractions; quadratic irrationalities
Subject:
Let $L$ be an elliptic differential operator of order $l>n/2$ in $R^n$. Let $\Omega\subset R^n$ be a bounded domain with Lipshitz boundary. The estimate $$-AG(x,x)^{1/2}G(y,y)^{1/2}\le G(x,y), x,y\in\Omega,$$ where $A