270 research outputs found
Symmetric vortices for two-component Ginzburg-Landau systems
We study Ginzburg--Landau equations for a complex vector order parameter
Psi=(psi_+,psi_-). We consider symmetric (equivariant) vortex solutions in the
plane R^2 with given degrees n_\pm, and prove existence, uniqueness, and
asymptotic behavior of solutions for large r. We also consider the monotonicity
properties of solutions, and exhibit parameter ranges in which both vortex
profiles |psi_+|, |psi_i| are monotone, as well as parameter regimes where one
component is non-monotone. The qualitative results are obtained by means of a
sub- and supersolution construction and a comparison theorem for elliptic
systems.Comment: 32 page
Vortex density models for superconductivity and superfluidity
We study some functionals that describe the density of vortex lines in
superconductors subject to an applied magnetic field, and in Bose-Einstein
condensates subject to rotational forcing, in quite general domains in 3
dimensions. These functionals are derived from more basic models via
Gamma-convergence, here and in a companion paper. In our main results, we use
these functionals to obtain descriptions of the critical applied magnetic field
(for superconductors) and forcing (for Bose-Einstein), above which ground
states exhibit nontrivial vorticity, as well as a characterization of the
vortex density in terms of a non local vector-valued generalization of the
classical obstacle problem.Comment: 34 page
Required Separation to Mitigate Pounding of Adjacent Building Blocks
This research discusses the feasibility of using the required minimum separation distance based on SBC 301-2007. Moment resistance frames were designed with expansion joints requiring 400mm separation distance. Nonlinear response history analysis was conducted with four ground motions selected and scaled to match the risk-targeted response spectrum of NEOM city based on ASCE 7-16 provisions. An equivalent spring constant value based on floor lateral stiffness was selected as a gap link stiffness. Finally, an evaluation for the pounding response of adjacent blocks is presented along with the conclusions
Vortex Rings in Fast Rotating Bose-Einstein Condensates
When Bose-Eintein condensates are rotated sufficiently fast, a giant vortex
phase appears, that is the condensate becomes annular with no vortices in the
bulk but a macroscopic phase circulation around the central hole. In a former
paper [M. Correggi, N. Rougerie, J. Yngvason, {\it arXiv:1005.0686}] we have
studied this phenomenon by minimizing the two dimensional Gross-Pitaevskii
energy on the unit disc. In particular we computed an upper bound to the
critical speed for the transition to the giant vortex phase. In this paper we
confirm that this upper bound is optimal by proving that if the rotation speed
is taken slightly below the threshold there are vortices in the condensate. We
prove that they gather along a particular circle on which they are evenly
distributed. This is done by providing new upper and lower bounds to the GP
energy.Comment: to appear in Archive of Rational Mechanics and Analysi
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