6352305
ABJM with Flavors and FQHE
We add fundamental matters to the = 6 Chern-Simons theory (ABJM theory), and show that D6-branes wrapped over AdS4 × S3/2 in type IIA superstring theory on AdS4 × 3 give its dual description with = 3 supersymmetry. We confirm this by the arguments based on R-symmetry, supersymmetry, and brane configuration of ABJM theory. We also analyze the fluctuations of the D6-brane and compute the conformal dimensions of dual operators. In the presence of fractional branes, the ABJM theory can model the fractional quantum Hall effect (FQHE), with RR-fields regarded as the external electric-magnetic field. We show that an addition of the flavor D6-brane describes a class of fractional quantum Hall plateau transitions.
119484634
R2 corrections for 5D black holes and rings
We study higher-order corrections to two BPS solutions of 5D supergravity, namely the supersymmetric black ring and the spinning black hole. Due to our current relatively limited understanding of F-type terms in 5D supergravity, the nature of these corrections is less clear than that of their 4D cousins. Effects of certain R2 terms found in Calabi-Yau compactification of M-theory are specifically considered. For the case of the black ring, for which the microscopic origin of the entropy is generally known, the corresponding higher order macroscopic correction to the entropy is found to match a microscopic correction, while for the spinning black hole the corrections are partially matched to those of a 4D D0−D2−D6 black hole.
119304446
Perturbations of W(infinity) CFTs
The holographic duals of higher spin theories on AdS_3 are described by the large N limit of a family of minimal model CFTs, whose symmetry algebra is equivalent to W(infinity)[lambda]. We study perturbations of these limit theories, and show that they possess a marginal symmetry-preserving perturbation that describes switching on the 1/N corrections. We also test our general results for the specific cases of lambda=0,1, where free field realisations are available.
16051323
Comment on `Cosmological Topological Massive Gravitons and Photons'
In a recent paper (arXiv: 0801.4566) it was shown that all global energy eigenstates of asymptotically $AdS_3$ chiral gravity have non-negative energy at the linearized level. This result was questioned (arXiv: 0803.3998) by Carlip, Deser, Waldron and Wise (CDWW), who work on the Poincare patch. They exhibit a linearized solution of chiral gravity and claim that it has negative energy and is smooth at the boundary. We show that the solution of CDWW is smooth only on that part of the boundary of $AdS_3$ included in the Poincare patch. Extended to global $AdS_3$, it is divergent at the boundary point not included in the Poincare patch. Hence it is consistent with the results of (arXiv: 0801.4566).
53121461
Quantum decoherence with holography
A bstractQuantum decoherence is the loss of a system’s purity due to its interaction with the surrounding environment. Via the AdS/CFT correspondence, we study how a system decoheres when its environment is a strongly-coupled theory. In the FeynmanVernon formalism, we compute the influence functional holographically by relating it to the generating function of Schwinger-Keldysh propagators and thereby obtain the dynamics of the system’s density matrix.We present two exactly solvable examples: (1) a straight string in a BTZ black hole and (2) a scalar probe in AdS5. We prepare an initial state that mimics Schrödinger’s cat and identify different stages of its decoherence process using the time-scaling behaviors of Rényi entropy. We also relate decoherence to local quantum quenches, and by comparing the time evolution behaviors of the Wigner function and Rényi entropy we demonstrate that the relaxation of local quantum excitations leads to the collapse of its wave-function.
119529056
Supersymmetric Probes in a Rotating 5D Attractor
Abstract Supersymmetric zero-brane and one-brane probes in the squashed AdS 2 × S 3 near-horizon geometry of the BMPV black hole are studied. Supersymmetric zero-brane probes stabilized by orbital angular momentum on the S 3 are found and shown to saturate a BPS bound. We also find supersymmetric one-brane probes which have momentum and winding around a U ( 1 ) L × U ( 1 ) R torus in the S 3 and in some cases are static.
118965499
Reading the Spectra of the Most Peculiar Type Ia Supernova 2002cx
In spite of the apparent lack of Si ii and S ii features in its spectra, SN 2002cx was classified as a peculiar Type Ia supernova (SN Ia) on the basis of its overall photometric and spectroscopic behavior. Spectra obtained near maximum light contained Fe iii features, as in SN 1991T-like events, but the blueshifts of the Fe iii absorptions were exceptionally low. The luminosity was also low. We use the supernova synthetic-spectrum code SYNOW to study line identifications in SN 2002cx. We find that the maximum-light spectra appear to contain weak features of Si ii, S ii, Si iii, and Ca ii, which strengthens the connection with SN 1991T-like events. We show that later spectra obtained 12, 25, and 56 days after maximum consist of P Cygni resonance-scattering features due to permitted Fe ii and Co ii lines. SN 2002cx had been thought to have made the transition from a permitted-line to a forbidden-line spectrum between 25 and 56 days. Owing to the low expansion velocities, the postmaximum spectral features are narrower and easier to identify than they are in other SNe Ia. SN 2002cx will lead to improved line identifications in other SNe Ia and will clarify when the transition from a permitted- to a forbidden-line spectrum occurs. In the context of current SN Ia explosion models, we suggest that the properties of SN 2002cx might be consistent with three-dimensional deflagration models, which are not favored for normal SNe Ia.
7659445
Uncovering the Putative B-star Binary Companion of the SN 1993J Progenitor
The Type IIb supernova (SN) 1993J is one of only a few stripped-envelope SNe with a progenitor star identified in pre-explosion images. SN IIb models typically invoke H envelope stripping by mass transfer in a binary system. For the case of SN 1993J, the models suggest that the companion grew to 22 M_☉ and became a source of ultraviolet (UV) excess. Located in M81, at a distance of only 3.6 Mpc, SN 1993J offers one of the best opportunities to detect the putative companion and test the progenitor model. Previously published near-UV spectra in 2004 showed evidence for absorption lines consistent with a hot (B2 Ia) star, but the field was crowded and dominated by flux from the SN. Here we present Hubble Space Telescope Cosmic Origins Spectrograph and Wide-Field Camera 3 observations of SN 1993J from 2012, at which point the flux from the SN had faded sufficiently to potentially measure the UV continuum properties from the putative companion. The resulting UV spectrum is consistent with contributions from both a hot B star and the SN, although we cannot rule out line-of-sight coincidences.
25008570
No-go theorems for unitary and interacting partially massless spin-two fields.
We examine the generic theory of a paratially massless (PM) spin-two field interacting with gravity in four dimensions from a bottom-up perspective. By analyzing the most general form of the Lagrangian, we first show that if such a theory exists, its de Sitter background must admit either so(1,5) or so(2,4) global symmetry depending on the relative sign of the kinetic terms: the former for a positive sign the latter for a negative sign. Further analysis reveals that the coupling constant of the PM cubic self-interaction must be fixed with a purely imaginary number in the case of a positive sign. We conclude that there cannot exist a unitary theory of a PM spin-two field coupled to Einstein gravity with a perturbatively local Lagrangian. In the case of a negative sign we recover conformal gravity. As a special case of our analysis, it is shown that the PM limit of massive gravity also lacks the PM gauge symmetry.
126042366
The Very Young Type-Ia SN 2012cg: Discovery and Pre-Maximum Brightness Follow-Up
119292700
Matter fields near quantum critical point in (2+1)-dimensional U(1) gauge theory
We study chiral phase transition and confinement of matter fields in (2+1)-dimensional U(1) gauge theory of massless Dirac fermions and scalar bosons. The vanishing scalar boson mass, r = 0, defines a quantum critical point between the Higgs phase and the Coulomb phase. We consider only the critical point r = 0 and the Coulomb phase with r > 0. The Dirac fermion acquires a dynamical mass when its flavor is less than certain critical value N c f , which depends quantitatively on the flavor Nb and the scalar boson mass r. When Nf < N c f , the matter fields carrying internal gauge charge are all confined if r 6 0 but are deconfined at the quantum critical point r = 0. The system has distinct low-energy elementary excitations at the critical point r = 0 and in the Coulomb phase with r 6 0. We calculate the specific heat and susceptibility of the system at r = 0 and r 6 0, which can help to detect the quantum critical point and to judge whether dynamical fermion mass generation takes place.