505 research outputs found
Space-time dependent couplings in N=1 SUSY gauge theories: Anomalies and Central Functions
We consider N=1 supersymmetric gauge theories in which the couplings are
allowed to be space-time dependent functions. Both the gauge and the
superpotential couplings become chiral superfields. As has recently been shown,
a new topological anomaly appears in models with space-time dependent gauge
coupling. Here we show how this anomaly may be used to derive the NSVZ beta
function in a particular, well-determined renormalisation scheme, both without
and with chiral matter. Moreover we extend the topological anomaly analysis to
theories coupled to a classical curved superspace background, and use it to
derive an all-order expression for the central charge c, the coefficient of the
Weyl tensor squared contribution to the conformal anomaly. We also comment on
the implications of our results for the central charge a expected to be of
relevance for a four-dimensional C-theorem.Comment: 28 pages, LaTeX, no figure
Hawking Radiation from AdS Black Holes
We investigate Hawking radiation from black holes in (d+1)-dimensional
anti-de Sitter space. We focus on s-waves, make use of the geometrical optics
approximation, and follow three approaches to analyze the radiation. First, we
compute a Bogoliubov transformation between Kruskal and asymptotic coordinates
and compare the different vacua. Second, following a method due to Kraus,
Parikh, and Wilczek, we view Hawking radiation as a tunneling process across
the horizon and compute the tunneling probablility. This approach uses an
anti-de Sitter version of a metric originally introduced by Painleve for
Schwarzschild black holes. From the tunneling probability one also finds a
leading correction to the semi-classical emission rate arising from the
backreaction to the background geometry. Finally, we consider a spherically
symmetric collapse geometry and the Bogoliubov transformation between the
initial vacuum state and the vacuum of an asymptotic observer.Comment: 13 pages, latex2e, v2: some clarifications and references adde
The beta function of N=1 SYM in Differential Renormalization
Using differential renormalization, we calculate the complete two-point
function of the background gauge superfield in pure N=1 Supersymmetric
Yang-Mills theory to two loops. Ultraviolet and (off-shell) infrared
divergences are renormalized in position and momentum space respectively. This
allows us to reobtain the beta function from the dependence on the ultraviolet
renormalization scale in an infrared-safe way. The two-loop coefficient of the
beta function is generated by the one-loop ultraviolet renormalization of the
quantum gauge field via nonlocal terms which are infrared divergent on shell.
We also discuss the connection of the beta function to the flow of the
Wilsonian coupling.Comment: 20 pages, 2 figures. Reference added, minor correction
Konishi anomaly approach to gravitational F-terms
We study gravitational corrections to the effective superpotential in
theories with a single adjoint chiral multiplet, using the generalized Konishi
anomaly and the gravitationally deformed chiral ring. We show that the genus
one correction to the loop equation in the corresponding matrix model agrees
with the gravitational corrected anomaly equations in the gauge theory. An
important ingrediant in the proof is the lack of factorization of chiral gauge
invariant operators in presence of a supergravity background. We also find a
genus zero gravitational correction to the superpotential, which can be removed
by a field redefinition.Comment: 28 pages, uses JHEP3.cl
Chiral rings, anomalies and loop equations in N=1* gauge theories
We examine the equivalence between the Konishi anomaly equations and the
matrix model loop equations in N=1* gauge theories, the mass deformation of N=4
supersymmetric Yang-Mills. We perform the superfunctional integral of two
adjoint chiral superfields to obtain an effective N=1 theory of the third
adjoint chiral superfield. By choosing an appropriate holomorphic variation,
the Konishi anomaly equations correctly reproduce the loop equations in the
corresponding three-matrix model. We write down the field theory loop equations
explicitly by using a noncommutative product of resolvents peculiar to N=1*
theories. The field theory resolvents are identified with those in the matrix
model in the same manner as for the generic N=1 gauge theories. We cover all
the classical gauge groups. In SO/Sp cases, both the one-loop holomorphic
potential and the Konishi anomaly term involve twisting of index loops to
change a one-loop oriented diagram to an unoriented diagram. The field theory
loop equations for these cases show certain inhomogeneous terms suggesting the
matrix model loop equations for the RP2 resolvent.Comment: 23 pages, 3 figures, latex2e, v4: minor changes in introduction and
conclusions, 4 references are added, version to appear in JHE
Vacuum Fluctuations, Geometric Modular Action and Relativistic Quantum Information Theory
A summary of some lines of ideas leading to model-independent frameworks of
relativistic quantum field theory is given. It is followed by a discussion of
the Reeh-Schlieder theorem and geometric modular action of Tomita-Takesaki
modular objects associated with the quantum field vacuum state and certain
algebras of observables. The distillability concept, which is significant in
specifying useful entanglement in quantum information theory, is discussed
within the setting of general relativistic quantum field theory.Comment: 26 pages. Contribution for the Proceedings of a Conference on Special
Relativity held at Potsdam, 200
Generalised quantum weakest preconditions
Generalisation of the quantum weakest precondition result of D'Hondt and
Panangaden is presented. In particular the most general notion of quantum
predicate as positive operator valued measure (POVM) is introduced. The
previously known quantum weakest precondition result has been extended to cover
the case of POVM playing the role of a quantum predicate. Additionally, our
result is valid in infinite dimension case and also holds for a quantum
programs defined as a positive but not necessary completely positive
transformations of a quantum states.Comment: 7 pages, no figures, added references, changed conten
Evolution, appearance, and occupational success
Visual characteristics, including facial appearance, are thought to play an important role in a variety of judgments and decisions that have real occupational outcomes in many settings. Indeed, there is growing evidence suggesting that appearance influences hiring decisions and even election results. For example, attractive individuals are more likely to be hired, taller men earn more, and the facial appearance of candidates has been linked to real election outcomes. In this article, we review evidence linking physical appearance to occupational success and evaluate the hypothesis that appearance based biases are consistent with predictions based on evolutionary theories of coalition formation and leadership choice. We discuss why appearance based effects are so pervasive, addressing ideas about a "kernel of truth" in attributions and about coalitional psychology. We additionally highlight that appearance may be differently related to success at work according to the types of job or task involved. For example, leaders may be chosen because the characteristics they possess are seen as best suited to lead in particular situations. During a time of war, a dominant-appearing leader may inspire confidence and intimidate enemies while during peace-time, when negotiation and diplomacy are needed, interpersonal skills may outweigh the value of a dominant leader. In line with these ideas, masculine-faced leaders are favored in war-time scenarios while feminine-faced leaders are favored in peace-time scenarios. We suggest that such environment or task specific competencies may be prevalent during selection processes, whereby individuals whose appearance best matches perceived task competences are most likely selected, and propose the general term "task-congruent selection" to describe these effects. Overall, our review highlights how potentially adaptive biases could influence choices in the work place. With respect to certain biases, understanding their origin and current prevalence is important in order to potentially reduce discrimination in the work place
QPMC: A model checker for quantum programs and protocols
© Springer International Publishing Switzerland 2015. We present QPMC (Quantum Program/Protocol Model Checker), an extension of the probabilistic model checker ISCASMC to automatically verify quantum programs and quantum protocols. QPMC distinguishes itself from the previous quantum model checkers proposed in the literature in that it works for general quantum programs and protocols, not only those using Clifford operations. A command-line version of QPMC is available at http://iscasmc.ios.ac.cn/tool/qmc/
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