25,924 research outputs found
Supersymmetry anomalies in conformal supergravity
We solve the Wess-Zumino consistency conditions of off-shell
conformal supergravity in four dimensions and determine the general form of the
superconformal anomalies for arbitrary and anomaly coefficients to
leading non trivial order in the gravitino. Besides the well known Weyl and
-symmetry anomalies, we compute explicitly the fermionic - and
-supersymmetry anomalies. In particular, we show that
-supersymmetry is anomalous if and only if -symmetry is
anomalous. The - and -supersymmetry anomalies give
rise to an anomalous supersymmetry transformation for the supercurrent on
curved backgrounds admitting Killing spinors, resulting in a deformed rigid
supersymmetry algebra. Our results may have implications for supersymmetric
localization and supersymmetry phenomenology. Analogous results are expected to
hold in dimensions two and six and for other supergravity theories. The present
analysis of the Wess-Zumino consistency conditions reproduces the holographic
result of arxiv:1703.04299 and generalizes it to arbitrary and anomaly
coefficients.Comment: 13+13 pages; v2: minor corrections and improvements; references
added; v3: further minor typos corrected; version published in JHE
Status of the LBNE Neutrino Beamline
The Long Baseline Neutrino Experiment (LBNE) will utilize a neutrino beamline
facility located at Fermilab to carry out a compelling research program in
neutrino physics. The facility will aim a beam of neutrinos toward a detector
placed at the Homestake Mine in South Dakota. The neutrinos are produced in a
three-step process. First, protons from the Main Injector (60-120 GeV) hit a
solid target and produce mesons. Then, the charged mesons are focused by a set
of focusing horns into the decay pipe, towards the far detector. Finally, the
mesons that enter the decay pipe decay into neutrinos. The parameters of the
facility were determined taking into account several factors including the
physics goals, the Monte Carlo modeling of the facility, spacial and
radiological constraints and the experience gained by operating the NuMI
facility at Fermilab. The initial beam power is expected to be ~700 kW, however
some of the parameters were chosen to be able to deal with a beam power of 2.3
MW. We discuss here the status of the conceptual design and the associated
challenges.Comment: 6 pages, 3 figure
Sparse Covers for Sums of Indicators
For all , we show that the set of Poisson Binomial
distributions on variables admits a proper -cover in total
variation distance of size ,
which can also be computed in polynomial time. We discuss the implications of
our construction for approximation algorithms and the computation of
approximate Nash equilibria in anonymous games.Comment: PTRF, to appea
AdS/CFT correspondence and Geometry
In the first part of this paper we provide a short introduction to the
AdS/CFT correspondence and to holographic renormalization. We discuss how QFT
correlation functions, Ward identities and anomalies are encoded in the bulk
geometry. In the second part we develop a Hamiltonian approach to the method of
holographic renormalization, with the radial coordinate playing the role of
time. In this approach regularized correlation functions are related to
canonical momenta and the near-boundary expansions of the standard approach are
replaced by covariant expansions where the various terms are organized
according to their dilatation weight. This leads to universal expressions for
counterterms and one-point functions (in the presence of sources) that are
valid in all dimensions. The new approach combines optimally elements from all
previous methods and supersedes them in efficiency.Comment: 30 pages, for Proceedings of the Strasburg meeting on AdS/CFT; v2:
additional Comments, refs adde
Lifshitz holography: The whole shebang
We provide a general algorithm for constructing the holographic dictionary
for any asymptotically locally Lifshitz background, with or without
hyperscaling violation, and for any values of the dynamical exponents and
, as well as the vector hyperscaling violating exponent, that are
compatible with the null energy condition. The analysis is carried out for a
very general bottom up model of gravity coupled to a massive vector field and a
dilaton with arbitrary scalar couplings. The solution of the radial
Hamilton-Jacobi equation is obtained recursively in the form of a graded
expansion in eigenfunctions of two commuting operators, which are the
appropriate generalization of the dilatation operator for non scale invariant
and Lorentz violating boundary conditions. The Fefferman-Graham expansions, the
sources and 1-point functions of the dual operators, the Ward identities, as
well as the local counterterms required for holographic renormalization all
follow from this asymptotic solution of the radial Hamilton-Jacobi equation. We
also find a family of exact backgrounds with and corresponding
to a marginal deformation shifting the vector hyperscaling violating parameter
and we present an example where the conformal anomaly contains the only
conformal invariant in with four spatial derivatives.Comment: 83 pages, 1 figur
More Supersymmetric Standard-like Models from Intersecting D6-branes on Type IIA Orientifolds
We present new classes of supersymmetric Standard-like models from type IIA
\IT^6/(\IZ_2\times \IZ_2) orientifold with intersecting D6-branes. D6-branes
can wrap general supersymmetric three-cycles of \IT^6=\IT^2\times \IT^2\times
\IT^2, and any \IT^2 is allowed to be tilted. The models still suffer from
additional exotics, however we obtained solutions with fewer Higgs doublets, as
well as models with all three families of left-handed quarks and leptons
arising from the same intersecting sector, and examples of a genuine left-right
symmetric model with three copies of left-handed and right-handed families of
quarks and leptons.Comment: 16 pages, REVTEX
Correlation Functions in Holographic RG Flows
We discuss the computation of correlation functions in holographic RG flows.
The method utilizes a recently developed Hamiltonian version of holographic
renormalization and it is more efficient than previous methods. A significant
simplification concerns the treatment of infinities: instead of performing a
general analysis of counterterms, we develop a method where only the
contribution of counterterms to any given correlator needs to be computed. For
instance, the computation of renormalized 2-point functions requires only an
analysis at the linearized level. We illustrate the method by discussing flat
and AdS-sliced domain walls. In particular, we discuss correlation functions of
the Janus solution, a recently discovered non-supersymmetric but stable
AdS-sliced domain wall.Comment: 33 pages, v2 additional material on Janus solution, typos corrected,
refs added, v3 additional comments on Janus solution, figure added, version
to appear in JHE
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