664 research outputs found
Intertwining Relations for the Deformed D1D5 CFT
The Higgs branch of the D1D5 system flows in the infrared to a
two-dimensional N=(4,4) SCFT. This system is believed to have an "orbifold
point" in its moduli space where the SCFT is a free sigma model with target
space the symmetric product of copies of four-tori; however, at the orbifold
point gravity is strongly coupled and to reach the supergravity point one needs
to turn on the four exactly marginal deformations corresponding to the blow-up
modes of the orbifold SCFT. Recently, technology has been developed for
studying these deformations and perturbing the D1D5 CFT off its orbifold point.
We present a new method for computing the general effect of a single
application of the deformation operators. The method takes the form of
intertwining relations that map operators in the untwisted sector before
application of the deformation operator to operators in the 2-twisted sector
after the application of the deformation operator. This method is
computationally more direct, and may be of theoretical interest. This line of
inquiry should ultimately have relevance for black hole physics.Comment: latex, 23 pages, 3 figure
New instability of non-extremal black holes: spitting out supertubes
We search for stable bound states of non-extremal rotating three-charge black
holes in five dimensions (Cvetic-Youm black holes) and supertubes. We do this
by studying the potential of supertube probes in the non-extremal black hole
background and find that generically the marginally bound state of the
supersymmetric limit becomes metastable and disappears with non-extremality
(higher temperature). However near extremality there is a range of parameters
allowing for stable bound states, which have lower energy than the
supertube-black hole merger. Angular momentum is crucial for this effect. We
use this setup in the D1-D5 decoupling limit to map a thermodynamic instability
of the CFT (a new phase which is entropically dominant over the black hole
phase) to a tunneling instability of the black hole towards the supertube-black
hole bound state. This generalizes the results of ArXiv:1108.0411 [hep-th],
which mapped an entropy enigma in the bulk to the dual CFT in a supersymmetric
setup.Comment: 28 pages + appendix, 15 figures, v2: References added, typos
corrected. Version published in JHE
Comments on black holes I: The possibility of complementarity
We comment on a recent paper of Almheiri, Marolf, Polchinski and Sully who
argue against black hole complementarity based on the claim that an infalling
observer 'burns' as he approaches the horizon. We show that in fact
measurements made by an infalling observer outside the horizon are
statistically identical for the cases of vacuum at the horizon and radiation
emerging from a stretched horizon. This forces us to follow the dynamics all
the way to the horizon, where we need to know the details of Planck scale
physics. We note that in string theory the fuzzball structure of microstates
does not give any place to 'continue through' this Planck regime. AMPS argue
that interactions near the horizon preclude traditional complementarity. But
the conjecture of 'fuzzball complementarity' works in the opposite way: the
infalling quantum is absorbed by the fuzzball surface, and it is the resulting
dynamics that is conjectured to admit a complementary description.Comment: 34 pages, 6 figures, v3: clarifications & references adde
The Nuts and Bolts of Einstein-Maxwell Solutions
We find new non-supersymmetric solutions of five-dimensional ungauged
supergravity coupled to two vector multiplets. The solutions are regular,
horizonless and have the same asymptotic charges as non-extremal charged black
holes. An essential ingredient in our construction is a four-dimensional
Euclidean base which is a solution to Einstein-Maxwell equations. We construct
stationary solutions based on the Euclidean dyonic Reissner-Nordstrom black
hole as well as a six-parameter family with a dyonic Kerr-Newman-NUT base.
These solutions can be viewed as compactifications of eleven-dimensional
supergravity on a six-torus and we discuss their brane interpretation.Comment: 29 pages, 3 figure
Emission from the D1D5 CFT: Higher Twists
We study a certain class of nonextremal D1D5 geometries and their ergoregion
emission. Using a detailed CFT computation and the formalism developed in
arXiv:0906.2015 [hep-th], we compute the full spectrum and rate of emission
from the geometries and find exact agreement with the gravity answer.
Previously, only part of the spectrum had been reproduced using a CFT
description. We close with a discussion of the context and significance of the
calculation.Comment: 39 pages, 6 figures, late
Excitations in the deformed D1D5 CFT
We perform some simple computations for the first order deformation of the
D1D5 CFT off its orbifold point. It had been shown earlier that under this
deformation the vacuum state changes to a squeezed state (with the further
action of a supercharge). We now start with states containing one or two
initial quanta and write down the corresponding states obtained under the
action of deformation operator. The result is relevant to the evolution of an
initial excitation in the CFT dual to the near extremal D1D5 black hole: when a
left and a right moving excitation collide in the CFT, the deformation operator
spreads their energy over a larger number of quanta, thus evolving the state
towards the infrared.Comment: 26 pages, Latex, 4 figure
Deforming the D1D5 CFT away from the orbifold point
The D1D5 brane bound state is believed to have an `orbifold point' in its
moduli space which is the analogue of the free Yang Mills theory for the D3
brane bound state. The supergravity geometry generated by D1 and D5 branes is
described by a different point in moduli space, and in moving towards this
point we have to deform the CFT by a marginal operator: the `twist' which links
together two copies of the CFT. In this paper we find the effect of this
deformation operator on the simplest physical state of the CFT -- the Ramond
vacuum. The twist deformation leads to a final state that is populated by pairs
of excitations like those in a squeezed state. We find the coefficients
characterizing the distribution of these particle pairs (for both bosons and
fermions) and thus write this final state in closed form.Comment: 30 pages, 4 figures, Late
Non-extremal Black Hole Microstates: Fuzzballs of Fire or Fuzzballs of Fuzz ?
We construct the first family of microstate geometries of near-extremal black
holes, by placing metastable supertubes inside certain scaling supersymmetric
smooth microstate geometries. These fuzzballs differ from the classical black
hole solution macroscopically at the horizon scale, and for certain probes the
fluctuations between various fuzzballs will be visible as thermal noise far
away from the horizon. We discuss whether these fuzzballs appear to infalling
observers as fuzzballs of fuzz or as fuzzballs of fire. The existence of these
solutions suggests that the singularity of non-extremal black holes is resolved
all the way to the outer horizon and this "backwards in time" singularity
resolution can shed light on the resolution of spacelike cosmological
singularities.Comment: 34 pages, 10 figure
Supergoop Dynamics
We initiate a systematic study of the dynamics of multi-particle systems with
supersymmetric Van der Waals and electron-monopole type interactions. The
static interaction allows a complex continuum of ground state configurations,
while the Lorentz interaction tends to counteract this configurational fluidity
by magnetic trapping, thus producing an exotic low temperature phase of matter
aptly named supergoop. Such systems arise naturally in gauge
theories as monopole-dyon mixtures, and in string theory as collections of
particles or black holes obtained by wrapping D-branes on internal space
cycles. After discussing the general system and its relation to quiver quantum
mechanics, we focus on the case of three particles. We give an exhaustive
enumeration of the classical and quantum ground states of a probe in an
arbitrary background with two fixed centers. We uncover a hidden conserved
charge and show that the dynamics of the probe is classically integrable. In
contrast, the dynamics of one heavy and two light particles moving on a line
shows a nontrivial transition to chaos, which we exhibit by studying the
Poincar\'e sections. Finally we explore the complex dynamics of a probe
particle in a background with a large number of centers, observing hints of
ergodicity breaking. We conclude by discussing possible implications in a
holographic context.Comment: 35 pages,11 figures. v2: updated references to include a previous
proof of classical integrability, exchanged a figure for a prettier versio
Effects of Feeding Bt MON810 Maize to Pigs for 110 Days on Peripheral Immune Response and Digestive Fate of the cry1Ab Gene and Truncated Bt Toxin
peer-reviewedBackground:
The objective of this study was to evaluate potential long-term (110 days) and age-specific effects of feeding genetically modified Bt maize on peripheral immune response in pigs and to determine the digestive fate of the cry1Ab gene and truncated Bt toxin.
Methodology/Principal Findings:
Forty day old pigs (n = 40) were fed one of the following treatments: 1) isogenic maize-based diet for 110 days (isogenic); 2) Bt maize-based diet (MON810) for 110 days (Bt); 3) Isogenic maize-based diet for 30 days followed by Bt maize-based diet for 80 days (isogenic/Bt); and 4) Bt maize-based diet (MON810) for 30 days followed by isogenic maize-based diet for 80 days (Bt/isogenic). Blood samples were collected during the study for haematological analysis, measurement of cytokine and Cry1Ab-specific antibody production, immune cell phenotyping and cry1Ab gene and truncated Bt toxin detection. Pigs were sacrificed on day 110 and digesta and organ samples were taken for detection of the cry1Ab gene and the truncated Bt toxin. On day 100, lymphocyte counts were higher (P<0.05) in pigs fed Bt/isogenic than pigs fed Bt or isogenic. Erythrocyte counts on day 100 were lower in pigs fed Bt or isogenic/Bt than pigs fed Bt/isogenic (P<0.05). Neither the truncated Bt toxin nor the cry1Ab gene were detected in the organs or blood of pigs fed Bt maize. The cry1Ab gene was detected in stomach digesta and at low frequency in the ileum but not in the distal gastrointestinal tract (GIT), while the Bt toxin fragments were detected at all sites in the GIT.
Conclusions/Significance:
Perturbations in peripheral immune response were thought not to be age-specific and were not indicative of Th 2 type allergenic or Th 1 type inflammatory responses. There was no evidence of cry1Ab gene or Bt toxin translocation to organs or blood following long-term feeding.The research leading to these results has received funding from the European Union’s Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 211820 and the Teagasc Walsh Fellowship programme
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