arXiv subjects

Burkhard Kleihaus

Publications and source records attributed to Burkhard Kleihaus.

140 records · Page 8Linked to original sources

arXiv1997

Static Axially Symmetric Einstein-Yang-Mills-Dilaton Solutions: II.Black Hole Solutions

We discuss the new class of static axially symmetric black hole solutions obtained recently in Einstein-Yang-Mills and Einstein-Yang-Mills-dilaton theory. These black hole solutions are asymptotically flat and they possess a regular event horizon. The event horizon is almost spherically symmetric with a slight elongation along the symmetry axis. The energy density of the matter fields is angle-dependent at the horizon. The static axially symmetric black hole solutions satisfy a simple relation between mass, dilaton charge, entropy and temperature. The black hole solutions are characterized by two integers, the winding number $n$ and the node number $k$ of the purely magnetic gauge field. With increasing node number the magnetically neutral black hole solutions form sequences tending to limiting solutions with magnetic charge $n$, corresponding to Einstein-Maxwell-dilaton black hole solutions for finite dilaton coupling constant and to Reissner-Nordstrøm black hole solutions for vanishing dilaton coupling constant.

gr-qc↗

arXiv1997

Charged SU(N) Einstein-Yang-Mills Black Holes

We consider asymptotically flat static spherically symmetric black hole solutions in SU(N) Einstein-Yang-Mills theory. Embedding the N-dimensional representation of $su(2)$ in $su(N)$, the purely magnetic gauge field ansatz contains $N-1$ functions. When one or more of these gauge field functions are identically zero, magnetically charged EYM black hole solutions emerge, consisting of a neutral and a charged gauge field part, based on non-abelian subalgebras and the Cartan subalgebra of $su(N)$, respectively. We classify these charged black hole solutions in general and present numerical solutions for SU(5) EYM theory.

hep-th↗

arXiv1997

Limiting solutions of sequences of globally regular and black hole solutions in SU(N)-EYMD theories

Static spherically symmetric solutions in SU(N)-EYM and EYMD theories are classified by the node numbers of their non-trivial gauge field functions. With increasing node numbers, the solutions form sequences, tending to limiting solutions. The limiting solutions are based on subalgebras of $su(N)$, consisting of a neutral non-abelian part and a charged abelian part, belonging to the Cartan subalgebra

gr-qc↗

arXiv1997

Static Axially Symmetric Einstein-Yang-Mills-Dilaton Solutions: I.Regular Solutions

We discuss the static axially symmetric regular solutions, obtained recently in Einstein-Yang-Mills and Einstein-Yang-Mills-dilaton theory [1]. These asymptotically flat solutions are characterized by the winding number $n>1$ and the node number $k$ of the purely magnetic gauge field. The well-known spherically symmetric solutions have winding number $n=1$. The axially symmetric solutions satisfy the same relations between the metric and the dilaton field as their spherically symmetric counterparts. Exhibiting a strong peak along the $ρ$-axis, the energy density of the matter fields of the axially symmetric solutions has a torus-like shape. For fixed winding number $n$ with increasing node number $k$ the solutions form sequences. The sequences of magnetically neutral non-abelian axially symmetric regular solutions with winding number $n$ tend to magnetically charged abelian spherically symmetric limiting solutions, corresponding to ``extremal'' Einstein-Maxwell-dilaton solutions for finite values of $γ$ and to extremal Reissner-Nordstrøm solutions for $γ=0$, with $n$ units of magnetic charge.

gr-qc↗

arXiv1997

Static black hole solutions with axial symmetry

We construct a new class of asymptotically flat black hole solutions in Einstein-Yang-Mills and Einstein-Yang-Mills-dilaton theory. These black hole solutions are static, and they have a regular event horizon. However, they possess only axial symmetry. Like their regular counterparts, the black hole solutions are characterized by two integers, the winding number $n$ and the node number $k$ of the gauge field functions.

gr-qc↗

arXiv1996

Static Axially Symmetric Solutions of Einstein-Yang-Mills-Dilaton Theory

We construct static axially symmetric solutions of SU(2) Einstein-Yang-Mills-dilaton theory. Like their spherically symmetric counterparts, these solutions are nonsingular and asymptotically flat. The solutions are characterized by the winding number n and the node number k of the gauge field functions. For fixed n with increasing k the solutions tend to ``extremal'' Einstein-Maxwell-dilaton black holes with n units of magnetic charge.

hep-th↗

arXiv1996

Axially Symmetric Multisphalerons in Yang-Mills-Dilaton Theory

We construct sequences of axially symmetric multisphaleron solutions in SU(2) Yang-Mills-dilaton theory. The sequences are labelled by a winding number $n>1$. For $n=1$ the known sequence of spherically symmetric sphaleron solutions is obtained. The solutions within each sequence are labelled by the number of nodes $k$ of the gauge field functions. The limiting solutions of the sequences correspond to abelian magnetic monopoles with $n$ units of charge and energy $E \propto n$.

hep-th↗

arXiv1996

Sequences of Einstein-Yang-Mills-Dilaton Black Holes

Einstein-Yang-Mills-dilaton theory possesses sequences of neutral static spherically symmetric black hole solutions. The solutions depend on the dilaton coupling constant $γ$ and on the horizon. The SU(2) solutions are labelled by the number of nodes $n$ of the single gauge field function, whereas the SO(3) solutions are labelled by the nodes $(n_1,n_2)$ of both gauge field functions. The SO(3) solutions form sequences characterized by the node structure $(j,j+n)$, where $j$ is fixed. The sequences of magnetically neutral solutions tend to magnetically charged limiting solutions. For finite $j$ the SO(3) sequences tend to magnetically charged Einstein-Yang-Mills-dilaton solutions with $j$ nodes and charge $P=\sqrt{3}$. For $j=0$ and $j \rightarrow \infty$ the SO(3) sequences tend to Einstein-Maxwell-dilaton solutions with magnetic charges $P=\sqrt{3}$ and $P=2$, respectively. The latter also represent the scaled limiting solutions of the SU(2) sequence. The convergence of the global properties of the black hole solutions, such as mass, dilaton charge and Hawking temperature, is exponential. The degree of convergence of the matter and metric functions of the black hole solutions is related to the relative location of the horizon to the nodes of the corresponding regular solutions.

hep-th↗

arXiv1995

SU(3) Einstein-Yang-Mills-Dilaton Sphalerons and Black Holes

SU(3) Einstein-Yang-Mills-dilaton theory possesses sequences of static spherically symmetric sphaleron and black hole solutions for the SU(2) and the SO(3) embedding. The solutions depend on the dilaton coupling constant $γ$, approaching the corresponding Einstein-Yang-Mills solutions for $γ\rightarrow 0$, and Yang-Mills-dilaton solutions in flat space for $γ\rightarrow \infty$. The sequences of solutions tend to Einstein-Maxwell-dilaton solutions with different magnetic charges. The solutions satisfy analogous relations between the dilaton field and the metric for general $γ$. Thermodynamic properties of the black hole solutions are discussed.

hep-th↗

arXiv1995

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.

hep-ph↗

arXiv1995

SU(3) Einstein-Yang-Mills Sphalerons and Black Holes

In the SU(3) Einstein-Yang-Mills system sequences of static spherically symmetric regular solutions and black hole solutions exist for both the SU(2) and the SO(3) embedding. We construct the lowest regular solutions of the SO(3) embedding, missed previously, and the corresponding black holes. The SO(3) solutions are classified according to their boundary conditions and the number of nodes of the matter functions. Both, the regular and the black hole solutions are unstable.

hep-th↗

arXiv1995

SU(3) Einstein-Skyrme Solitons and Black Holes

In the SU(3) Einstein-Skyrme system static spherically symmetric particle-like solutions and black holes exist for both the SU(2) and the SO(3) embedding. The SO(3) embedding leads to new particle-like solutions and black holes, sharing many features with the SU(2) solutions. In particular, there are always two branches of solutions, forming a cusp at a critical coupling constant. The regular SO(3) solutions have even topological charge $B$. The mass of the $B=2$ SO(3) solutions is less than twice the mass of the $B=1$ SU(2) solutions. We conjecture, that the lowest SO(3) branches correspond to stable particle-like solutions and stable black holes.

hep-th↗

arXiv1994

Multisphalerons in the Weinberg-Salam Theory

We construct multisphaleron solutions in the Weinberg-Salam theory. The multisphaleron solutions carry Chern-Simons charge $n/2$, where $n$ is an integer, counting the winding of the fields in the azimuthal angle. The well-known sphaleron has $n=1$. The multisphalerons possess axial symmetry and parity reflection symmetry. We vary the Higgs mass and the mixing angle. For small $n$ the energies of the multisphalerons are on the order of $n$ times the energy of the sphaleron and their magnetic dipole moments are on the order of $n$ times the magnetic dipole moment of the sphaleron.

hep-ph↗

arXiv1994

Multisphalerons in the Weak Interactions

We construct multisphaleron solutions in the weak interactions. The multisphaleron solutions carry Chern-Simons charge $n/2$, where $n$ is an integer. The well-known sphaleron has $n=1$ and is spherically symmetric for vanishing mixing angle. In contrast the multisphalerons with $n>1$ are only axially symmetric, even for vanishing mixing angle. The greater $n$, the stronger the energy density deforms. While for small Higgs masses the energy of the multisphalerons is smaller than $n$ times the energy of the sphaleron, the energy of the multisphalerons is larger than $n$ times the energy of the sphaleron for large Higgs masses.

hep-ph↗