5,005 research outputs found
On Axially Symmetric Solutions in the Electroweak Theory
We present the general ansatz, the energy density and the Chern-Simons charge
for static axially symmetric configurations in the bosonic sector of the
electroweak theory. Containing the sphaleron, the multisphalerons and the
sphaleron-antisphaleron pair at finite mixing angle, the ansatz further allows
the construction of the sphaleron and multisphaleron barriers and of the
bisphalerons at finite mixing angle. We conjecture that further solutions
exist.Comment: 17 pages, latex, THU-94/0
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
Rotating Boson Stars in 5 Dimensions
We study rotating boson stars in five spacetime dimensions. The boson fields
consist of a complex doublet scalar field. Considering boson stars rotating in
two orthogonal planes with both angular momenta of equal magnitude, a special
ansatz for the boson field and the metric allows for solutions with nontrivial
dependence on the radial coordinate only. The charge of the scalar field equals
the sum of the angular momenta. The rotating boson stars are globally regular
and asymptotically flat. For our choice of a sixtic potential the rotating
boson star solutions possess a flat spacetime limit. We study the solutions in
flat and curved spacetime.Comment: 17 pages, 6 figure
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
Vapor chamber fin studies. Operating characteristics of fin models
Operating characteristics and limits of vapor chamber fins or heat pipe
Sphalerons, spectral flow, and anomalies
The topology of configuration space may be responsible in part for the
existence of sphalerons. Here, sphalerons are defined to be static but unstable
finite-energy solutions of the classical field equations. Another manifestation
of the nontrivial topology of configuration space is the phenomenon of spectral
flow for the eigenvalues of the Dirac Hamiltonian. The spectral flow, in turn,
is related to the possible existence of anomalies. In this review, the
interconnection of these topics is illustrated for three particular sphalerons
of SU(2) Yang-Mills-Higgs theory.Comment: 35 pages with revtex4; invited paper for the August special issue of
JMP on "Integrability, topological solitons and beyond
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
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