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.
14507542
Fractional quantum Hall effect via holography: Chern-Simons, edge states and hierarchy
We present three holographic constructions of fractional quantum Hall effect (FQHE) via string theory. The first model studies edge states in FQHE using supersymmetric domain walls in = 6 Chern-Simons theory. We show that D4-branes wrapped on 1 or D8-branes wrapped on 3 create edge states that shift the rank or the level of the gauge group, respectively. These holographic edge states correctly reproduce the Hall conductivity. The second model presents a holographic dual to the pure U(N)k (Yang-Mills-)Chern-Simons theory based on a D3-D7 system. Its holography is equivalent to the level-rank duality, which enables us to compute the Hall conductivity and the topological entanglement entropy. The third model introduces the first string theory embedding of hierarchical FQHEs, using IIA string on 2/Zn.
54005042
Modular properties of 3D higher spin theory
A bstractIn the three-dimensional $ \mathfrak{s}\mathfrak{l} $(N) Chern-Simons higher-spin theory, we prove that the conical surplus and the black hole solution are related by the S-transformation of the modulus of the boundary torus. Then applying the modular group on a given conical surplus solution, we generate a ‘SL(2, $ \mathbb{Z} $)’ family of smooth constant solutions. We then show how these solutions are mapped into one another by coordinate transformations that act non-trivially on the homology of the boundary torus.After deriving a thermodynamics that applies to all the solutions in the ‘SL(2, $ \mathbb{Z} $)’ family, we compute their entropies and free energies, and determine how the latter transform under the modular transformations. Summing over all the modular images of the conical surplus, we write down a (tree-level) modular invariant partition function.
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).
14536751
Some No-go Theorems for String Duals of Non-relativistic Lifshitz-like Theories
We study possibilities of string theory embeddings of the gravity duals for non-relativistic Lifshitz-like theories with anisotropic scale invariance. We search classical solutions in type IIA and eleven-dimensional supergravities which are expected to be dual to (2+1)-dimensional Lifshitz-like theories. Under reasonable ansatze, we prove that such gravity duals in the supergravities are not possible. We also discuss a possible physical reason behind this.
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.
125944692
High-p(T) di-hadron and jet-hadron correlations in p p and PbPb collisions
119219249
Nearby supernova rates from the Lick Observatory Supernova Search – IV. A recovery method for the delay-time distribution
Recovery of the supernova (SN) delay-time distribution (DTD) – the SN rate versus time that would follow a hypothetical brief burst of star formation – can shed light on SN progenitors and physics, as well as on the time-scales of chemical enrichment. Previous attempts to reconstruct the DTD have been based either on comparison of mean SN rates versus redshift to cosmic star-formation history (SFH), or on the comparison of SN rates among galaxies with different mean ages. Here, we present an approach to recover the SN DTD that avoids the averaging and loss of information of other schemes. We compare the SFHs of individual galaxies to the numbers of SNe discovered by a survey in each galaxy (generally zero, sometimes one SN, rarely a few). We apply the method to a subsample of 3505 galaxies, hosting 82 type-Ia SNe (SNe Ia) and 119 core-collapse supernovae (CC SNe), from the Lick Observatory Supernova Search (LOSS), that have SFHs reconstructed from Sloan Digital Sky Survey (SDSS) spectra. We find a >2σ SN Ia DTD signal in our shortest-delay, ‘prompt’ bin at 99 per cent confidence level. We further find a 4σ indication of SNe Ia that are ‘delayed’ by >2.4 Gyr. Thus, the data support the existence of both prompt and delayed SNe Ia. We measure the time integral over the SN DTD. For CC SNe we find a total yield of 0.010 ± 0.002
118344568
Holographic p-wave superconductors in quasi-topological gravity
We construct a holographic p-wave superconductor model in the framework of quasi-topological gravity in the probe limit. The relation between the critical temperature and the coupling parameters of higher curvature terms is investigated. The numerical results for conductivity are presented as well. It turns out that our data fit the Drude model very well in the low-frequency limit, and the values of dc conductivity as well as the relaxation time are obtained numerically.
119261799
Holographic superconductors in quasi-topological gravity
In this paper we study (3+1) dimensional holographic superconductors in quasi-topological gravity which is recently proposed by R. Myers et.al.. Through both analytical and numerical analysis, we find in general the condensation becomes harder with the increase of coupling parameters of higher curvature terms. In particular, comparing with those in ordinary Gauss-Bonnet gravity, we find that positive cubic corrections in quasi-topological gravity suppress the condensation while negative cubic terms make it easier. We also calculate the conductivity numerically for various coupling parameters. It turns out that the universal relation of ωg/Tc ≃ 8 is unstable and this ratio becomes larger with the increase of the coupling parameters. A brief discussion on the condensation from the CFT side is also presented.
17558930
New Wolf-Rayet Galaxies with Detection of WC Stars
We report the discovery of two new Wolf-Rayet (W-R) galaxies: Mrk 1039 and F08208+2816. Two broad W-R bumps at 5808 and 4650 A indicate the presence of early-type WC (WCE) and late-type WN (WNL) star populations in both sources. We also confirm the presence of W-R features in Mrk 35, previously detected in a different position. The observed equivalent width of the W-R bump at 4650 A and the derived number ratios of W-R/(W-R+O) imply that star formation in these sources takes place in short burst durations. Comparisons with the recent models of W-R populations in young starbursts with the observed EW(He II λ4686), EW(C IV λ5808), and EW(W-R bump) and their relative intensities provide an indication that the stellar initial mass function in some W-R galaxies might not be Salpeter-like. It is interesting to find that the luminous IRAS source F08208+2816 has little dust reddening, probably because of the existence of a powerful superwind. By comparisons with other starbursts observed with the Hopkins Ultraviolet Telescope, F08208+2816 as a merging system renders a chance to study the contribution from young starbursts to the UV background radiation in the universe.