10,106 research outputs found
Hydrodynamic fluctuations in relativistic superfluids
The Hamiltonian formulation of superfluids based on noncanonical Poisson
brackets is studied in detail. The assumption that the momentum density is
proportional to the flow of the conserved energy is shown to lead to the
covariant relativistic theory previously suggested by Khalatnikov, Lebedev and
Carter, and some potentials in this theory are given explicitly. We discuss
hydrodynamic fluctuations in the presence of dissipative effects and we derive
the corresponding set of hydrodynamic correlation functions. Kubo relations for
the transport coefficients are obtained.Comment: 13 pages, no figures, two references adde
Simulation of Beam-Beam Effects and Tevatron Experience
Effects of electromagnetic interactions of colliding bunches in the Tevatron
had a variety of manifestations in beam dynamics presenting vast opportunities
for development of simulation models and tools. In this paper the computer code
for simulation of weak-strong beam-beam effects in hadron colliders is
described. We report the collider operational experience relevant to beam-beam
interactions, explain major effects limiting the collider performance and
compare results of observations and measurements with simulations.Comment: 23 pages, 17 figure
Baxter operator and Archimedean Hecke algebra
In this paper we introduce Baxter integral Q-operators for finite-dimensional
Lie algebras gl(n+1) and so(2n+1). Whittaker functions corresponding to these
algebras are eigenfunctions of the Q-operators with the eigenvalues expressed
in terms of Gamma-functions. The appearance of the Gamma-functions is one of
the manifestations of an interesting connection between Mellin-Barnes and
Givental integral representations of Whittaker functions, which are in a sense
dual to each other. We define a dual Baxter operator and derive a family of
mixed Mellin-Barnes-Givental integral representations. Givental and
Mellin-Barnes integral representations are used to provide a short proof of the
Friedberg-Bump and Bump conjectures for G=GL(n+1) proved earlier by Stade. We
also identify eigenvalues of the Baxter Q-operator acting on Whittaker
functions with local Archimedean L-factors. The Baxter Q-operator introduced in
this paper is then described as a particular realization of the explicitly
defined universal Baxter operator in the spherical Hecke algebra H(G(R),K), K
being a maximal compact subgroup of G. Finally we stress an analogy between
Q-operators and certain elements of the non-Archimedean Hecke algebra
H(G(Q_p),G(Z_p)).Comment: 32 pages, typos corrected
Classical and relativistic dynamics of supersolids: variational principle
We present a phenomenological Lagrangian and Poisson brackets for obtaining
nondissipative hydrodynamic theory of supersolids. A Lagrangian is constructed
on the basis of unification of the principles of non-equilibrium thermodynamics
and classical field theory. The Poisson brackets, governing the dynamics of
supersolids, are uniquely determined by the invariance requirement of the
kinematic part of the found Lagrangian. The generalization of Lagrangian is
discussed to include the dynamics of vortices. The obtained equations of motion
do not account for any dynamic symmetry associated with Galilean or Lorentz
invariance. They can be reduced to the original Andreev-Lifshitz equations if
to require Galilean invariance. We also present a relativistic-invariant
supersolid hydrodynamics, which might be useful in astrophysical applications.Comment: 22 pages, changed title and content, added reference
- …
