1,177 research outputs found
Unconventional state with two coexisting long-range orders for frustrated Heisenberg model at quantum phase transition
For the frustrated two-dimensional antiferromagnetic Heisenberg model
close to quantum phase transition we consider the singlet ground states
retaining both translational and SU(2) symmetry. Besides usually discussed
checkerboard, spin-liquid and stripe states an unconventional state with two
coexisting long-range orders appears to be possible at sufficiently large
damping of spin excitations. The problem is treated in the frames of
self-consistent spherically symmetric approach.Comment: 11 pages, 5 figure
Gaseous Radiochemical Method for Registration of Ionizing Radiation and Its Possible Applications in Science and Industry
This work presents a new possibility of registration of ionizing radiation by
the flowing gaseous radiochemical method (FGRM). The specified method uses the
property of some solid crystalline lattice materials for a free emission of
radioactive isotopes of inert gas atoms formed as a result of nuclear
reactions. Generated in an ampoule of the detector, the radioactive inert gases
are transported by a gas-carrier into the proportional gas counter of the
flowing type, where the decay rate of the radioactive gas species is measured.
This quantity is unequivocally related to the flux of particles (neutrons,
protons, light and heavy ions) at the location of the ampoule. The method was
used to monitor the neutron flux of the pulsed neutron target "RADEX" driven by
the linear proton accelerator of INR RAS. Further progress of the FGRM may give
rise to possible applications in nuclear physics, astrophysics and medicine, in
the nondestructive control of fissionable materials, diagnostics of
thermonuclear plasma, monitoring of fluxes and measurement of spectra of
bombarding particles.Comment: 19 pages, 5 figure
Spin-Orbit-Like Terms in Semileptonic Weak Hamiltonian
It is shown that new spin-orbit-like terms appear in the effective
nonrelativistic weak Hamiltonian for nucleon provided that nuclear potential is
taken into account. Arguments for their considerable enhancement, in
particular, in relativistic nuclear model of Walecka are advanced.Comment: 3 pages, latex, no figures, submitted to the European Physical
Journal
A relaxation scheme for computation of the joint spectral radius of matrix sets
The problem of computation of the joint (generalized) spectral radius of
matrix sets has been discussed in a number of publications. In the paper an
iteration procedure is considered that allows to build numerically Barabanov
norms for the irreducible matrix sets and simultaneously to compute the joint
spectral radius of these sets.Comment: 16 pages, 2 figures, corrected typos, accepted for publication in
JDE
The MañéâConzeâGuivarc'h lemma for intermittent maps of the circle
We study the existence of solutions g to the functional inequality fâ€g Tâg+ÎČ, where f is a prescribed continuous function, T is a weakly expanding transformation of the circle having an indifferent fixed point, and ÎČ is the maximum ergodic average of f. Using a method due to T. Bousch, we show that continuous solutions g always exist when the Hölder exponent of f is close to 1. In the converse direction, we construct explicit examples of continuous functions f with low Hölder exponent for which no continuous solution g exists. We give sharp estimates on the best possible Hölder regularity of a solution g given the Hölder regularity of f
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