31 research outputs found
Non Supersymmetric Metastable Vacua in N=2 SYM Softly Broken to N=1
We find non-supersymmetric metastable vacua in four dimensional N=2 gauge
theories softly broken to N=1 by a superpotential term. First we study the
simplest case, namely the SU(2) gauge theory without flavors. We study the
spectrum and lifetime of the metastable vacuum and possible embeddings of the
model in UV complete theories. Then we consider larger gauge group theories
with flavors. We show that when we softly break them to N=1, the potential
induced on specific submanifolds of their moduli space is identical to the
potential in lower rank gauge theories. Then we show that the potential
increases when we move away from this submanifold, allowing us to construct
metastable vacua on them in the theories that can be reduced to the SU(2) case.Comment: 29 pages, 10 figure
Supersymmetry Breaking Vacua from M Theory Fivebranes
We consider intersecting brane configurations realizing N=2 supersymmetric
gauge theories broken to N=1 by multitrace superpotentials, and softly to N=0.
We analyze, in the framework of M5-brane wrapping a curve, the supersymmetric
vacua and the analogs of spontaneous supersymmetry breaking and soft
supersymmetry breaking in gauge theories. We show that the M5-brane does not
exhibit the analog of metastable spontaneous supersymmetry breaking, and does
not have non-holomorphic minimal volume curves with holomorphic boundary
conditions. However, we find that any point in the N=2 moduli space can be
rotated to a non-holomorphic minimal volume curve, whose boundary conditions
break supersymmetry. We interpret these as the analogs of soft supersymmetry
breaking vacua in the gauge theory.Comment: 32 pages, 8 figures, harvmac; v2: corrections in eq. 3.6 and in
section 6, reference adde
Entropy Bound and Causality Violation in Higher Curvature Gravity
In any quantum theory of gravity we do expect corrections to Einstein gravity
to occur. Yet, at fundamental level, it is not apparent what the most relevant
corrections are. We argue that the generic curvature square corrections present
in lower dimensional actions of various compactified string theories provide a
natural passage between the classical and quantum realms of gravity. The
Gauss-Bonnet and gravities, in particular, provide concrete
examples in which inconsistency of a theory, such as, a violation of
microcausality, and a classical limit on black hole entropy are correlated. In
such theories the ratio of the shear viscosity to the entropy density,
, can be smaller than for a boundary conformal field theory with
Einstein gravity dual. This result is interesting from the viewpoint that the
nuclear matter or quark-gluon plasma produced (such as at RHIC) under extreme
densities and temperatures may violate the conjectured bound , {\it albeit} marginally so.Comment: 23 pages, several eps figures; minor changes, references added,
published versio
Dynamical Supersymmetry Breaking from Meta-stable Vacua in an N=1 Supersymmetric Gauge Theory
We investigate supersymmetry breaking meta-stable vacua in N=2, SU(2)\times
U(1) gauge theory with N_f=2 massless flavors perturbed by the addition of
small N=1 preserving mass terms in a presence of a Fayet-Iliopoulos term. We
derive the low energy effective theory by using the exact results of N=2
supersymmetric QCD and examine the effective potential. At the classical level,
the theory has supersymmetric vacua on Coulomb and Higgs branches. We find that
supersymmetry on the Coulomb branch is dynamically broken as a consequence of
the strong dynamics of SU(2) gauge symmetry while the supersymmetric vacuum on
the Higgs branch remains. We also estimate the lifetimes of the local minima on
the Coulomb branch. We find that they are sufficiently long and therefore the
local vacua we find are meta-stable.Comment: 24 pages, 13 figures, references adde
Thermal Evolution of the Non Supersymmetric Metastable Vacua in N=2 SU(2) SYM Softly Broken to N=1
It has been shown that four dimensional N=2 gauge theories, softly broken to
N=1 by a superpotential term, can accommodate metastable non-supersymmetric
vacua in their moduli space. We study the SU(2) theory at high temperatures in
order to determine whether a cooling universe settles in the metastable vacuum
at zero temperature. We show that the corrections to the free energy because of
the BPS dyons are such that may destroy the existence of the metastable vacuum
at high temperatures. Nevertheless we demonstrate the universe can settle in
the metastable vacuum, provided that the following two conditions are hold:
first the superpotential term is not arbitrarily small in comparison to the
strong coupling scale of the gauge theory, and second the metastable vacuum
lies in the strongly coupled region of the moduli space.Comment: 32 pages, 30 figure
Charged Rényi entropies in CFTs with Einstein-Gauss-Bonnet holographic duals
We calculate the Rényi entropy Sq (μ, λ), for spherical entangling surfaces in CFT’s with Einstein-Gauss-Bonnet-Maxwell holographic duals. Rényi entropies must obey some interesting inequalities by definition. However, for Gauss-Bonnet couplings λ, larger than specific value, but still allowed by causality, we observe a violation of the inequality (formula presented), which is related to the existence of negative entropy black holes, providing interesting restrictions in the bulk theory. Moreover, we find an interesting distinction of the behaviour of the analytic continuation of Sq (μ, λ) for imaginary chemical potential, between negative and non-negative λ. © 2014, The Author(s)