12,764 research outputs found

    Hamiltonian lattice quantum chromodynamics at finite density with Wilson fermions

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    Quantum chromodynamics (QCD) at sufficiently high density is expected to undergo a chiral phase transition. Understanding such a transition is of particular importance for neutron star or quark star physics. In Lagrangian SU(3) lattice gauge theory, the standard approach breaks down at large chemical potential ÎĽ\mu, due to the complex action problem. The Hamiltonian formulation of lattice QCD doesn't encounter such a problem. In a previous work, we developed a Hamiltonian approach at finite chemical potential ÎĽ\mu and obtained reasonable results in the strong coupling regime. In this paper, we extend the previous work to Wilson fermions. We study the chiral behavior and calculate the vacuum energy, chiral condensate and quark number density, as well as the masses of light hadrons. There is a first order chiral phase transition at zero temperature.Comment: 23 pages. Version accepted for publication in Physical Review

    Theory of optical imaging beyond the diffraction limit with a far-field superlens

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    Recent theoretical and experimental studies have shown that imaging with resolution well beyond the diffraction limit can be obtained with so-called superlenses. Images formed by such superlenses are, however, in the near field only, or a fraction of wavelength away from the lens. In this paper, we propose a far-field superlens (FSL) device which is composed of a planar superlens with periodical corrugation. We show in theory that when an object is placed in close proximity of such a FSL, a unique image can be formed in far-field. As an example, we demonstrate numerically that images of 40 nm lines with a 30 nm gap can be obtained from far-field data with properly designed FSL working at 376nm wavelength.Comment: 6 pages, 3 figure

    Estimates for Hilbertian Koszul homology

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    AbstractThe objective of this paper is to give new kind of estimates for Hilbertian Koszul homology, inspired by commutative algebra, in multivariable Fredholm theory
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