**Authors:** Fabrizio Canfora, Francisco Correa, Alex Giacomini, Julio Oliva

In this paper an intrinsically non-Abelian black hole solution for the SU(2)
Einstein-Yang-Mills theory in four dimensions is constructed. The gauge field
of this solution has the form of a meron whereas the metric is the one of a
Reissner-NordstrÃ¶m black hole in which, however, the coefficient of the
term is not an integration constant. Even if the stress-energy tensor
of the Yang-Mills field is spherically symmetric, the field strength of the
Yang-Mills field itself is not. A remarkable consequence of this fact, which
allows to distinguish the present solution from essentially Abelian
configurations, is the Jackiw, Rebbi, Hasenfratz, ‘t Hooft mechanism according
to which excitations of bosonic fields moving in the background of a gauge
field with this characteristic behave as Fermionic degrees of freedom.

1 year ago -

2
**Authors:** Liu Zhao, Wei Xu, Pengfei Yu

Every classical Newtonian mechanical system can be equipped with a
nonstandard Hamiltonian structure, in which the Hamiltonian is the square of
the canonical Hamiltonian up to a constant shift, and the Poisson bracket is
nonlinear. In such a formalism, time translation symmetry can be spontaneously
broken, provided the potential function becomes negative. A nice analogy
between time translation symmetry breaking and the Landau theory of second
order phase transitions is established, together with several example cases
illustrating time translation breaking ground states. In particular, the
CDM model of FRW cosmology is reformulated as the time translation
symmetry breaking ground states.

1 year ago

**Authors:** Louise Dolan, Yang Sun

We compute the partition function of five-dimensional abelian gauge theory on
a five-torus T5 with a general flat metric using the Dirac method of quantizing
with constraints. We compare this with the partition function of a single
fivebrane compactified on S1 times T5, which is obtained from the six-torus
calculation of Dolan and Nappi. The radius R1 of the circle S1 is set to the
dimensionful gauge coupling constant g^2= R1.

1 year ago

**Authors:** Matthias Ihl (Dublin Inst.), Arnab Kundu (Texas U.), Sandipan Kundu (Texas U., TCC and Texas U.)

We consider back-reaction by non-supersymmetric D7/anti-D7 probe branes in
the Kuperstein-Sonnenschein model at finite temperature. Using the smearing
technique, we obtain an analytical solution for the back-reacted background to
leading order in N_f/N_c. This back-reaction explicitly breaks the conformal
invariance and introduces a dimension 6 operator in the dual field theory which
is an irrelevant deformation of the original conformal field theory. We further
probe this back-reacted background by introducing an additional set of probe
brane/anti-brane. This additional probe sector undergoes a chiral phase
transition at finite temperature, which is absent when the back-reaction
vanishes. We investigate the corresponding phase diagram and the thermodynamics
associated with this phase transition. We also argue that additional probes do
not suffer from any instability caused by the back-reaction, which suggests
that this system is stable beyond the probe limit.

1 year ago

**Authors:** Takao Suyama

The planar resolvent for N=3 U(N)_k Chern-Simons theory coupled to an
arbitrary number of adjoint matters is determined. Analytic continuation of the
‘t Hooft coupling t is analyzed. The eigenvalue distribution turns out to be
confined in a finite region even for a large t. The vev of a Wilson loop does
not exhibit an exponential growth although such a behavior would be expected
for theories with classical gravity duals.

1 year ago

**Authors:** M. Aa. Solberg

We prove there is no symmetry which, imposed on the general charge
conjugation (C) invariant multi-Higgs-doublet model (NHDM), excludes exactly
the O(4) violating terms from the potential. This is in part done by
determining the exact subsymmetries of the custodial SO(4) symmetry of the
standard model (SM) scalar Lagrangian. Furthermore, the Higgs family symmetries
of the quadratic part of the general C invariant NHDM potential will also be
symmetries of the O(4) violating terms of the potential, and hence cannot be
applied to remove the O(4) violating terms from the potential. Finally,
negative determinant elements of O(4) cannot be applied to expel the O(4)
breaking terms from the NHDM potential either: We show there is no symmetries
of the kinetic Higgs terms in the negative determinant part of O(4). This is
also the case in the limit g’ -> 0. Hence the custodial SO(4) symmetry is the
largest symmetry group of the scalar sector of the SM in the limit g’ -> 0.

1 year ago

**Authors:** Claudio Coriano, Luigi Delle Rose, Carlo Marzo, Mirko Serino

We investigate the Standard Model in the nearly conformal limit, in which
conformal symmetry is broken only by the dilatation anomaly, through a
hierarchy of anomalous Ward identities for the divergence of its dilatation
current. In this approximation, the identities allow to extract the coupling of
the dilaton to the trace anomaly, which we compute up to the quartic order in
the conformal breaking scale. Our approach can be easily extended to discuss
the anomaly contributions to the dilaton effective action to an arbitrarily
high order. They allow to make a distinction between the Higgs and a dilaton at
a phenomenological level.

1 year ago

**Authors:** Rudolf Baier, Stefan A. Stricker, Olli Taanila, Aleksi Vuorinen

We study the production of prompt photons in strongly coupled
out-of-equilibrium Super Yang-Mills plasma using the AdS/CFT correspondence.
Our goal is to determine the photon emission spectrum at different stages of a
thermalization process, which is modeled via the gravitational collapse of a
thin spherical shell in AdS space. Particular emphasis is placed on the
limit of large frequencies, which we are able to treat analytically.

1 year ago

**Authors:** Martin Ammon, Veselin G. Filev, Javier Tarrio, Dimitrios Zoakos

We study the effects of the temperature and of a magnetic field in the setup
of an intersection of D3/D7 branes, where a large number of D7 branes is
smeared in the transverse directions to allow for a perturbative solution in a
backreaction parameter. The magnetic field sources an anisotropy in the plasma,
and we investigate its physical consequences for the thermodynamics and energy
loss of particles probing the system. In particular we comment on the
stress-energy tensor of the plasma, the propagation of sound in the directions
parallel and orthogonal to the magnetic field, the drag force of a quark moving
through the medium and jet quenching.

1 year ago

**Authors:** Christopher J. Fewster, Rainer Verch

Afshordi, Aslanbeigi and Sorkin have recently proposed a construction of a
distinguished “S-J state” for scalar field theory in (bounded regions of)
general curved spacetimes. We establish rigorously that the proposal is
well-defined on globally hyperbolic spacetimes or spacetime regions that can be
embedded as relatively compact subsets of other globally hyperbolic spacetimes,
and also show that, whenever the proposal is well-defined, it yields a pure
quasifree state. However, by explicitly considering portions of ultrastatic
spacetimes, we show that the S-J state is not in general a Hadamard state. In
the specific case where the Cauchy surface is a round 3-sphere, we prove that
the representation induced by the S-J state is generally not unitarily
equivalent to that of a Hadamard state, and indeed that the representations
induced by S-J states on nested regions of the ultrastatic spacetime also fail
to be unitarily equivalent in general. The implications of these results are
discussed.

1 year ago