4,680 research outputs found
D=5 Einstein-Maxwell-Chern-Simons Black Holes
5-dimensional Einstein-Maxwell-Chern-Simons theory with Chern-Simons
coefficient has supersymmetric black holes with vanishing horizon
angular velocity, but finite angular momentum. Here supersymmetry is associated
with a borderline between stability and instability, since for a
rotational instability arises, where counterrotating black holes appear, whose
horizon rotates in the opposite sense to the angular momentum. For
black holes are no longer uniquely characterized by their global charges, and
rotating black holes with vanishing angular momentum appear.Comment: 4 pages, 4 figures, RevTeX styl
Level Crossing Along Sphaleron Barriers
In the electroweak sector of the standard model topologically inequivalent
vacua are separated by finite energy barriers, whose height is given by the
sphale\-ron. For large values of the Higgs mass there exist several sphaleron
solutions and the barriers are no longer symmetric. We construct paths of
classical configurations from one vacuum to a neighbouring one and solve the
fermion equations in the background field configurations along such paths,
choosing the fermions of a doublet degenerate in mass. As in the case of light
Higgs masses we observe the level crossing phenomenon also for large Higgs
masses.Comment: 17 pages, latex, 10 figures in uuencoded postscript files. THU-94/0
Remoção de DQO, nitrogênio e sólidos de reator de lodos ativados no pós-tratamento de dejetos de suínos.
Projeto/Plano de Ação: 02.07.60.700-0
The Sphaleron Barrier in the Presence of Fermions
We calculate the minimal energy path over the sphaleron barrier in the
pre\-sen\-ce of fermions, assuming that the fermions of a doublet are
degenerate in mass. This allows for spherically symmetric ans\"atze for the
fields, when the mixing angle dependence is neglected. While light fermions
have little influence on the barrier, the presence of heavy fermions ( TeV) strongly deforms the barrier, giving rise to additional sphalerons
for very heavy fermions ( 10 TeV). Heavy fermions form
non-topological solitons in the vacuum sector.Comment: 19 pages, latex, 18 figures in 3 seperate uuencoded postscript files
THU-93/1
Nondegenerate Fermions in the Background of the Sphaleron Barrier
We consider level crossing in the background of the sphaleron barrier for
nondegenerate fermions. The mass splitting within the fermion doublets allows
only for an axially symmetric ansatz for the fermion fields. In the background
of the sphaleron we solve the partial differential equations for the fermion
functions. We find little angular dependence for our choice of ansatz. We
therefore propose a good approximate ansatz with radial functions only. We
generalize this approximate ansatz with radial functions only to fermions in
the background of the sphaleron barrier and argue, that it is a good
approximation there, too.Comment: LATEX, 20 pages, 11 figure
Multisphalerons in the Weinberg-Salam Theory
We construct multisphaleron solutions in the Weinberg-Salam theory. The
multisphaleron solutions carry Chern-Simons charge , where is an
integer, counting the winding of the fields in the azimuthal angle. The
well-known sphaleron has . The multisphalerons possess axial symmetry and
parity reflection symmetry. We vary the Higgs mass and the mixing angle. For
small the energies of the multisphalerons are on the order of times the
energy of the sphaleron and their magnetic dipole moments are on the order of
times the magnetic dipole moment of the sphaleron.Comment: 18 pages, latex, 17 figures in uuencoded postscript files. THU-94/1
Chaotic hysteresis in an adiabatically oscillating double well
We consider the motion of a damped particle in a potential oscillating slowly
between a simple and a double well. The system displays hysteresis effects
which can be of periodic or chaotic type. We explain this behaviour by
computing an analytic expression of a Poincar'e map.Comment: 4 pages RevTeX, 3 PS figs, uses psfig.sty. Submitted to Phys. Rev.
Letters. PS file also available at
http://dpwww.epfl.ch/instituts/ipt/berglund.htm
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