2,510,613 research outputs found
Theory of Polar Corrections to Donor Binding
We calculate the optical phonon correction to the binding energy of electrons
to donors in cubic materials. Previous theories calculated the Rydberg energy
reduced by the effective mass and the static dielectric function. They omitted
an important energy term from the long-range polarization of the ionized donor,
which vanishes for the neutral donor. They also omitted the donor-phonon
interaction. Including these terms yields a new formula for the donor binding
energy
Sensitivity of Cross Sections for Elastic Nucleus-Nucleus Scattering to Halo Nucleus Density Distributions
In order to clear up the sensitivity of the nucleus-nucleus scattering to the
nuclear matter distributions of exotic halo nuclei, we have calculated
differential cross sections for elastic scattering of the He and Li
nuclei on several nuclear targets at the energy of 0.8 GeV/nucleon with
different assumed nuclear density distributions in He and Li.Comment: 10 pages, 7 figures. Submitted to Proceedings of the 61 International
Conference "Nucleus-2011" on the Problems of the Nuclear Spectroscopy and the
Atomic Nuclear Structure, Sarov Nijzegorodskaya district, October 10-14, 201
Note on nonequilibrium stationary states and entropy
In transformations between nonequilibrium stationary states, entropy might be
a not well defined concept. It might be analogous to the ``heat content'' in
transformations in equilibrium which is not well defined either, if they are
not isochoric ({\it i.e.} do involve mechanical work). Hence we conjecture that
un a nonequilbrium stationary state the entropy is just a quantity that can be
transferred or created, like heat in equilibrium, but has no physical meaning
as ``entropy content'' as a property of the system.Comment: 4 page
Shear viscosity in magnetized neutron star crust
The electron shear viscosity due to Coulomb scattering of degenerate
electrons by atomic nuclei throughout a magnetized neutron star crust is
calculated. The theory is based on the shear viscosity coefficient calculated
neglecting magnetic fields but taking into account gaseous, liquid and solid
states of atomic nuclei, multiphonon scattering processes, and finite sizes of
the nuclei albeit neglecting the effects of electron band structure. The
effects of strong magnetic fields are included in the relaxation time
approximation with the effective electron relaxation time taken from the
field-free theory. The viscosity in a magnetized matter is described by five
shear viscosity coefficients. They are calculated and their dependence on the
magnetic field and other parameters of dense matter is analyzed. Possible
applications and open problems are outlined.Comment: 6 pages, 3 figures, EPL, accepte
The antifield Koszul-Tate complex of reducible Noether identities
A generic degenerate Lagrangian system of even and odd fields is examined in
algebraic terms of the Grassmann-graded variational bicomplex. Its
Euler-Lagrange operator obeys Noether identities which need not be independent,
but satisfy first-stage Noether identities, and so on. We show that, if a
certain necessary and sufficient condition holds, one can associate to a
degenerate Lagrangian system the exact Koszul-Tate complex with the boundary
operator whose nilpotency condition restarts all its Noether and higher-stage
Noether identities. This complex provides a sufficient analysis of the
degeneracy of a Lagrangian system for the purpose of its BV quantization.Comment: 23 page
Active vibration isolator for flexible bodies Patent
Vibration control of flexible bodies in steady accelerating environmen
Network representation of electromagnetic fields and forces using generalized bond graphs
We show that it is possible to describe electromagnetic (E-M) fields with a generalized network representation (generalized bond graphs). E-M fields inmoving matter, forces due to E-M fields (Lorentz force, ets.) and field transformations are included in the network description. The relations of these E-M phenomena with respect to each other are clearly represented by the bond graph. We also show that it is not possible to describe E-M phenomena in moving matter with conventional bond graphs, but that a generalized bond graph concept is required.\ud
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The description of simple E-M devices with conventional bond graphs is based on rather drastic assumptions, i.e. quasi-static conditions (E-M radiation neglected), homogeneous fields, isotropic linear material, etc. These assumptions are not made in this paper
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