161 research outputs found
Aspects of Quantum Fermionic T-duality
We study two aspects of fermionic T-duality: the duality in purely fermionic
sigma models exploring the possible obstructions and the extension of the
T-duality beyond classical approximation. We consider fermionic sigma models as
coset models of supergroups divided by their maximally bosonic subgroup
OSp(m|n)/SO(m) x Sp(n). Using the non-abelian T-duality and a non-conventional
gauge fixing we derive their fermionic T-duals. In the second part of the
paper, we prove the conformal invariance of these models at one and two loops
using the Background Field Method and we check the Ward Identities.Comment: 65 pages, 5 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
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
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
No Fermionic Wigs for BPS Attractors in 5 Dimensions
We analyze the fermionic wigging of 1/2-BPS (electric) extremal black hole
attractors in N=2, D=5 ungauged Maxwell-Einstein supergravity theories, by
exploiting anti-Killing spinors supersymmetry transformations. Regardless of
the specific data of the real special geometry of the manifold defining the
scalars of the vector multiplets, and differently from the D=4 case, we find
that there are no corrections for the near--horizon attractor value of the
scalar fields; an analogous result also holds for 1/2-BPS (magnetic) extremal
black string. Thus, the attractor mechanism receives no fermionic corrections
in D=5 (at least in the BPS sector).Comment: 24 pages, LaTeX2
VITRIFICATION OF BOVINE IVP EMBRYOS: AGE OF EMBRYOS AND EXPOSURE TIME TO CRYOPROTECTANT INFLUENCE VIABILITY
Avaliou-se diferentes tempos de exposição e concentrações de crioprotetores na vitrificação
de embriões bovinos PIV. No primeiro experimento, foram utilizados blastocistos do dia 7 (Bx-D7). No
tratamento 1 (T1), 82 embriões foram expostos por 1 min. à solução de equilÃbrio (SE1 = 10% EG + 10%
dimetilsulfóxido (DMSO), seguido da exposição por 20 segundos à solução de vitrificação (SV1 = 20%
EG + 20% DMSO). No Tratamento 2 (T2) 84 embriões foram expostos por 3 minutos à SE2 (8,25% EG
+ 8,25% DMSO), seguido de 45 segundos na SV2 (16,5% EG + 16,5% DMSO). No segundo experimento
adotou-se os mesmos procedimentos do primeiro, porém com Bx D8. A remoção dos crioprotetores foi
executado em duas etapas de cinco minutos, em 0,3 e 0,15M de sacarose. Os embriões foram incubados
por 72 horas, avaliando-se as taxas de re-expansão e eclosão (12 e 72 horas, respectivamente). No
primeiro experimento, a taxa de re-expansão no T1 (91,6%) foi superior a do T2 (82,0%) (p0,05). No segundo experimento,
as taxas de re-expansão não diferiram entre T1 e T2 (65,8 e 68,7% respectivamente), porém a taxa de
eclosão do T1 (51,7%) foi superior a do T2 (33,2%) (
Supersymmetric Fluid Dynamics
Recently Navier-Stokes (NS) equations have been derived from the duality
between the black branes and a conformal fluid on the boundary of AdS_5.
Nevertheless, the full correspondence has to be established between solutions
of supergravity in AdS_5 and supersymmetric field theories on the boundary.
That prompts the construction of NS equations for a supersymmetric fluid. In
the framework of rigid susy, there are several possibilities and we propose one
candidate. We deduce the equations of motion in two ways: both from the
divergenless condition on the energy-momentum tensor and by a suitable
parametrization of the auxiliary fields. We give the complete component
expansion and a very preliminary analysis of the physics of this supersymmetric
fluid.Comment: 24 pages, Latex2
Sex disparities in efficacy in covid-19 vaccines: A systematic review and meta-analysis
Sex differences in adaptive and innate immune responses have been shown to occur and anecdotal reports suggest that vaccine efficacy and safety may be sex-dependent. We investigated the influence of sex on the efficacy of COVID-19 vaccines through a systematic review and meta-analysis of clinical trials on COVID-19 vaccines. The safety profile of COVID-19 vaccines was also investigated. A systematic review included eligible articles published in three databases and three websites. A meta-analysis of available data, stratified by sex, was conducted. Statistical analysis was performed using the Hartung\u2013Knapp\u2013Sidik\u2013Jonkman method, as well as influence and heterogeneity analysis. Pooled analysis showed significantly higher efficacy, measured as the rate of new COVID-19 cases, in men compared to women in the vaccine group (OR = 0.67, 95% CI 0.48\u20130.94). No sex differences were found in the rate of new cases in the control group (OR = 0.92, 95% CI 0.78\u20131.09). Safety profiles derived from pharmacovigilance reports appear to indicate increased toxicity in women. In conclusion, evidence of a potential role of sex in COVID-19 vaccine efficacy was described. It strengthens the need to include sex as a core variable in the clinical trial design of COVID-19 vaccines
Fluid Super-Dynamics from Black Hole Superpartners
Recently the Navier-Stokes equations have been derived from the duality with
the black branes in AdS_5. The zero modes of black branes are reinterpreted as
dynamical degrees of freedom of a conformal fluid on the boundary of AdS_5.
Here, we derive the corrections to the Navier-Stokes equations due to fermionic
zero modes of the black branes. We study only the contributions due to
bilinears in the fermionic zero modes in the first order of the parameter
expansion. The need of a superextension of the fluid dynamics is a consequence
of the full AdS/CFT correspondence and yet to be investigated.Comment: 15 pages, LaTex2
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