5,912 research outputs found
Quantum integrability of the deformed elliptic Calogero-Moser problem
The integrability of the deformed quantum elliptic Calogero-Moser problem
introduced by Chalykh, Feigin and Veselov is proven. Explicit recursive
formulae for the integrals are found. For integer values of the parameter this
implies the algebraic integrability of the systems.Comment: 23 page
The AdS_5xS^5 superstring worldsheet S-matrix and crossing symmetry
An S-matrix satisying the Yang-Baxter equation with symmetries relevant to
the AdS_5xS^5 superstring has recently been determined up to an unknown scalar
factor. Such scalar factors are typically fixed using crossing relations,
however due to the lack of conventional relativistic invariance, in this case
its determination remained an open problem.
In this paper we propose an algebraic way to implement crossing relations for
the AdS_5xS^5 superstring worldsheet S-matrix. We base our construction on a
Hopf-algebraic formulation of crossing in terms of the antipode and introduce
generalized rapidities living on the universal cover of the parameter space
which is constructed through an auxillary, coupling constant dependent,
elliptic curve. We determine the crossing transformation and write functional
equations for the scalar factor of the S-matrix in the generalized rapidity
plane.Comment: 27 pages, no figures; v2: sign typo fixed in (24), everything else
unchange
Vacuum polarization induced by a uniformly accelerated charge
We consider a point charge fixed in the Rindler coordinates which describe a
uniformly accelerated frame. We determine an integral expression of the induced
charge density due to the vacuum polarization at the first order in the fine
structure constant. In the case where the acceleration is weak, we give
explicitly the induced electrostatic potential.Comment: 13 pages, latex, no figures, to appear in Int. J. Theor. Phys
Street Gangs and Coercive Control: The Gendered Exploitation of Young Women and Girls in County Lines
This paper explores young women and girls’ participation in gangs and ‘county lines’ drug sales. Qualitative interviews and focus groups with criminal justice and social service professionals found that women and girls in gangs often are judged according to androcentric, stereotypical norms that deny gender-specific risks of exploitation. Gangs capitalise on the relative ‘invisibility’ of young women to advance their economic interests in county lines and stay below police radar. The research shows gangs maintain control over women and girls in both physical and digital spaces via a combination of threatened and actual (sexual) violence and a form of economic abuse known as debt bondage; tactics readily documented in the field of domestic abuse. This paper argues that coercive control offers a new way of understanding and responding to these gendered experiences of gang life, with important implications for policy and practic
Partition function of the eight-vertex model with domain wall boundary condition
We derive the recursive relations of the partition function for the
eight-vertex model on an square lattice with domain wall boundary
condition. Solving the recursive relations, we obtain the explicit expression
of the domain wall partition function of the model. In the
trigonometric/rational limit, our results recover the corresponding ones for
the six-vertex model.Comment: Latex file, 20 pages; V2, references adde
Orienting coupled quantum rotors by ultrashort laser pulses
We point out that the non-adiabatic orientation of quantum rotors, produced
by ultrashort laser pulses, is remarkably enhanced by introducing dipolar
interaction between the rotors. This enhanced orientation of quantum rotors is
in contrast with the behavior of classical paired rotors, in which dipolar
interactions prevent the orientation of the rotors. We demonstrate also that a
specially designed sequence of pulses can most efficiently enhances the
orientation of quantum paired rotors.Comment: 7 pages, 5 figures, to appear in Phys. Rev.
Whittaker-Hill equation and semifinite-gap Schroedinger operators
A periodic one-dimensional Schroedinger operator is called semifinite-gap if
every second gap in its spectrum is eventually closed. We construct explicit
examples of semifinite-gap Schroedinger operators in trigonometric functions by
applying Darboux transformations to the Whittaker-Hill equation. We give a
criterion of the regularity of the corresponding potentials and investigate the
spectral properties of the new operators.Comment: Revised versio
Zero modes on cosmic strings in an external magnetic field
A classical analysis suggests that an external magnetic field can cause
trajectories of charge carriers on a superconducting domain wall or cosmic
string to bend, thus expelling charge carriers with energy above the mass
threshold into the bulk. We study this process by solving the Dirac equation
for a fermion of mass and charge , in the background of a domain wall
and a magnetic field of strength . We find that the modes of the charge
carriers get shifted into the bulk, in agreement with classical expectations.
However the dispersion relation for the zero modes changes dramatically --
instead of the usual linear dispersion relation, , the new
dispersion relation is well fit by where
for a thin wall in the weak field limit, and for a thick
wall of width . This result shows that the energy of the charge carriers on
the domain wall remains below the threshold for expulsion even in the presence
of an external magnetic field. If charge carriers are expelled due to an
additional perturbation, they are most likely to be ejected at the threshold
energy .Comment: 9 pages, 4 figure
Adiabatic-Impulse approximation for avoided level crossings: from phase transition dynamics to Landau-Zener evolutions and back again
We show that a simple approximation based on concepts underlying the
Kibble-Zurek theory of second order phase transition dynamics can be used to
treat avoided level crossing problems. The approach discussed in this paper
provides an intuitive insight into quantum dynamics of two level systems, and
may serve as a link between the theory of dynamics of classical and quantum
phase transitions. To illustrate these ideas we analyze dynamics of a
paramagnet-ferromagnet quantum phase transition in the Ising model. We also
present exact unpublished solutions of the Landau-Zener like problems.Comment: 12 pages & 6 figures, minor corrections, version accepted in Phys.
Rev.
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