The linear response of an electron–ion plasma to an applied oscillating electric field is studied within the framework of Bloch’s classical hydrodynamic model. The ions are assumed to be fixed in space and distributed according to a known probability distribution. The linearized equations of...

We give a new proof of the well-known upper bound on the correlation function of a gas of non-overlapping dipoles of fixed length and discrete orientation working directly in the charge representation, instead of the more usual sine-Gordon representation.

Invariance principle states that a scaled simple random walk converges to the standard Brownian motion.

In this paper we describe a Sequential Importance Sampling (SIS) procedure for counting the number of vertex covers in general graphs. The performance of SIS depends heavily on how close the SIS proposal distribution is to a uniform one over a suitably restricted set. The proposed algorithm...

Using local search method, this paper provides a polynomial time approximation scheme for the minimum vertex cover problem on <InlineEquation ID="IEq1"> <EquationSource Format="TEX">$$d$$</EquationSource> <EquationSource Format="MATHML"> <math xmlns:xlink="http://www.w3.org/1999/xlink"> <mi>d</mi> </math> </EquationSource> </InlineEquation>-dimensional ball graphs where <InlineEquation ID="IEq2"> <EquationSource Format="TEX">$$d \ge 3$$</EquationSource> <EquationSource Format="MATHML"> <math xmlns:xlink="http://www.w3.org/1999/xlink"> <mrow> <mi>d</mi> <mo>≥</mo> <mn>3</mn> </mrow> </math> </EquationSource> </InlineEquation>. The key to the proof is a new separator theorem for ball graphs in higher dimensional space....</equationsource></equationsource></inlineequation></equationsource></equationsource></inlineequation>