9,810 research outputs found
Fermionic Corrections to Fluid Dynamics from BTZ Black Hole
We reconstruct the complete fermionic orbit of the non-extremal BTZ black
hole by acting with finite supersymmetry transformations. The solution
satisfies the exact supergravity equations of motion to all orders in the
fermonic expansion and the final result is given in terms of fermionic
bilinears. By fluid/gravity correspondence, we derive linearized Navier-Stokes
equations and a set of new differential equations from Rarita-Schwinger
equation. We compute the boundary energy-momentum tensor and we interpret the
result as a perfect fluid with a modified definition of fluid velocity.
Finally, we derive the modified expression for the entropy of the black hole in
terms of the fermionic bilinears.Comment: 21 pages, Latex2e, no figure
Fermionic Wigs for BTZ Black Holes
We compute the wig for the BTZ black hole, namely the complete non-linear
solution of supergravity equations with all fermionic zero modes. We use a
"gauge completion" method starting from AdS_3 Killing spinors to generate the
gravitinos fields associated to the BH and we compute the back-reaction on the
metric. Due to the anticommutative properties of the fermionic hairs the
resummation of these effects truncates at some order. We illustrate the
technique proposed in a precedent paper in a very explicit and analytical form.
We also compute the mass, the angular momentum and other charges with their
corrections.Comment: 11 pages, no figure
Fermions, Wigs, and Attractors
We compute the modifications to the attractor mechanism due to fermionic
corrections. In N=2, D=4 supergravity, at the fourth order, we find a new
contribution to the horizon values of the scalar fields of the vector
multiplets.Comment: v2 : 1+11 pages; paper reorganized in Sections; Sec. 5 added, with
detailed treatment of the axion-dilaton model; some typos fixed and
references adde
Slavnov-Taylor Parameterization for the Quantum Restoration of BRST Symmetries in Anomaly-Free Gauge Theories
It is shown that the problem of the recursive restoration of the
Slavnov-Taylor (ST) identities at the quantum level for anomaly-free gauge
theories is equivalent to the problem of parameterizing the local approximation
to the quantum effective action in terms of ST functionals, associated with the
cohomology classes of the classical linearized ST operator. The ST functionals
of dimension <=4 correspond to the invariant counterterms, those of dimension
>4 generate the non-symmetric counterterms upon projection on the action-like
sector. At orders higher than one in the loop expansion there are additional
contributions to the non-invariant counterterms, arising from known lower order
terms. They can also be parameterized by using the ST functionals. We apply the
method to Yang-Mills theory in the Landau gauge with an explicit mass term
introduced in a BRST-invariant way via a BRST doublet. Despite being
non-unitary, this model provides a good example where the method devised in the
paper can be applied to derive the most general solution for the action-like
part of the quantum effective action, compatible with the fulfillment of the ST
identities and the other relevant symmetries of the model, to all orders in the
loop expansion. The full dependence of the solution on the normalization
conditions is given.Comment: 23 pages. Final version published in the journa
Efficacy of first-line sodium thiosulphate administration in a case of potassium cyanide poisoning
Cyanide poisoning may occur following accidental fire-smoke inhalation or deliberate ingestion of salts. Hydroxocobalamin represents a first-line life-saving antidote. Although hydroxocobalamin represents a first-line lifesaving antidote, it is still not promptly available in the emergency department. Sodium thiosulfate can be administered in association with hydroxocobalamin whereas the delayed onset of clinical response makes sodium thiosulfate less suitable for emergency use. We describe a case of cyanide intoxication of a 43-year-old man who ingested an unknown amount of potassium cyanide, purchased via the Internet, in an attempted suicide. At admission to the emergency department, the patient presented GCS 3 with severe lactic acidosis. Orotracheal intubation, gastric lavage and oral activated charcoal were applied. Sodium thiosulfate was available in the emergency department and 10 grams were infused over a 30 minute period. Hydroxocobalamin was prescribed by the poison control centre and 5 grams were infused 2 hours after admission. Following sodium thiosulfate administration the patient was arousable and lactate concentration improved. No adverse effects were noted. Metabolic acidosis completely resolved 12 hours later. Cyanide concentration performed on blood samples collected at admission confirmed high cyanide blood levels (15 mg/L). This report highlights as the first-line administration of sodium thiosulfate, in rapid infusion, resulted effective and safe for cyanide poisoning. Our report suggests that sodium thiosulfate should be considered when hydroxocobalamin is not promptly available in an emergency settin
An Introduction to the Covariant Quantization of Superstrings
We give an introduction to a new approach to the covariant quantization of
superstrings. After a brief review of the classical Green--Schwarz superstring
and Berkovits' approach to its quantization based on pure spinors, we discuss
our covariant formulation without pure spinor constraints. We discuss the
relation between the concept of grading, which we introduced to define vertex
operators, and homological perturbation theory, and we compare our work with
recent work by others. In the appendices, we include some background material
for the Green-Schwarz and Berkovits formulations, in order that this
presentation be self contained.Comment: LaTex, 23 pp. Contribution to the Proceedings of the Workshop in
String Theory, Leuven 2002, some references added and a comment on ref. [16
Noncommutativity relations in type IIB theory and their supersymmetry
In the present paper we investigate noncommutativity of and -brane
world-volumes embedded in space-time of type IIB superstring theory. Boundary
conditions, which preserve half of the initial supersymmetry, are treated as
canonical constraints. Solving the constraints we obtain original coordinates
in terms of the effective coordinates and momenta. Presence of momenta induces
noncommutativity of string endpoints. We show that noncommutativity relations
are connected by N=1 supersymmetry transformations and noncommutativity
parameters are components of N=1 supermultiplet
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