12,764 research outputs found
Hamiltonian lattice quantum chromodynamics at finite density with Wilson fermions
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 , 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 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
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
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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