Lodged in the throat: Internal infinities and AdS/CFT

In the context of AdS3/CFT2, we address spacetimes with a certain sort of internal infinity as typified by the extreme BTZ black hole. The internal infinity is a null circle lying at the end of the black hole's infinite throat. We argue that such spacetimes may be described by a product CFT of the form CFT-L * CFT-R, where CFT-R is associated with the asymptotically AdS boundary while CFT-L is associated with the null circle. Our particular calculations analyze the CFT dual of the extreme BTZ black hole in a linear toy model of AdS3/CFT2. Since the BTZ black hole is a quotient of AdS3, the dual CFT state is a corresponding quotient of the CFT vacuum state. This state turns out to live in the aforementioned product CFT. We discuss this result in the context of general issues of AdS/CFT duality and entanglement entropy.Comment: 11 pages, 2 figures; v2 - some typos corrected, minor revision

Cosmological equations and Thermodynamics on Apparent Horizon in Thick Braneworld

We derive the generalized Friedmann equation governing the cosmological evolution inside the thick brane model in the presence of two curvature correction terms: a four-dimensional scalar curvature from induced gravity on the brane, and a five-dimensional Gauss-Bonnet curvature term. We find two effective four-dimensional reductions of the Friedmann equation in some limits and demonstrate that they can be rewritten as the first law of thermodynamics on the apparent horizon of thick braneworld.Comment: 25 pages, no figure, a definition corrected, several references added, more motivation and discussio

Sub-wavelength lithography over extended areas

We demonstrate a systematic approach to sub-wavelength resolution lithographic image formation on films covering areas larger than a wavelength squared. For example, it is possible to make a lithographic pattern with a feature size resolution of $\lambda/[2(N+1)]$ by using a particular $2 M$-photon, multi-mode entangled state, where $N < M$, and banks of birefringent plates. By preparing a statistically mixed such a state one can form any pixel pattern on a $(N+1) 2^{M-N} \times (N+1) 2^{M-N}$ pixel grid occupying a square with a side of $L=2^{M-N-1}$ wavelengths. Hence, there is a trade-off between the exposed area, the minimum lithographic feature size resolution, and the number of photons used for the exposure. We also show that the proposed method will work even under non-ideal conditions, albeit with somewhat poorer performance.Comment: 8 pages, 8 figures, 1 table. Written in RevTe

Corrections to Hawking-like Radiation for a Friedmann-Robertson-Walker Universe

Recently, a Hamilton-Jacobi method beyond semiclassical approximation in black hole physics was developed by \emph{Banerjee} and \emph{Majhi}\cite{beyond0}. In this paper, we generalize their analysis of black holes to the case of Friedmann-Robertson-Walker (FRW) universe. It is shown that all the higher order quantum corrections in the single particle action are proportional to the usual semiclassical contribution. The corrections to the Hawking-like temperature and entropy of apparent horizon for FRW universe are also obtained. In the corrected entropy, the area law involves logarithmic area correction together with the standard inverse power of area term.Comment: 10 pages, no figures, comments are welcome; v2: references added and some typoes corrected, to appear in Euro.Phys.J.C; v3:a defect corrected. We thank Dr.Elias Vagenas for pointing out a defect of our pape

MarcoPolo-R: Near-Earth Asteroid sample return mission selected for the assessment study phase of the ESA program cosmic vision

This paper presents the sample return mission to a primitive Near-Earth Asteroid (NEA) MarcoPolo-R proposed to the European Space Agency in December 2010. MarcoPolo-R was selected in February 2011 with three other missions addressing different science objectives for the two-year Assessment Phase of the Medium-Class mission competition of the Cosmic Vision 2 program for launch in 2022. The baseline target of MarcoPolo-R is the binary NEA (175706) 1996 FG3, which offers an efficient operational and technical mission profile. A binary target also provides enhanced science return. The choice of a binary target allows several scientific investigations to occur more easily than through a single object, in particular regarding the fascinating geology and geophysics of asteroids. MarcoPolo-R will rendezvous with a primitive, organic-rich NEA, scientifically characterize it at multiple scales, and return a bulk sample to Earth for laboratory analyses. The MarcoPolo-R sample will provide a representative sample from the surface of a known asteroid with known geologic context, and will contribute to the inventory of primitive material that is probably missing from the meteorite collection. The MarcoPolo-R samples will thus contribute to the exploration of the origin of planetary materials and initial stages of habitable planet formation, to the identification and characterization of the organics and volatiles in a primitive asteroid and to the understanding of the unique geomorphology, dynamics and evolution of a binary asteroid that belongs to the Potentially Hazardous Asteroid (PHA) population

Trans-Planckian Effects in Inflationary Cosmology and the Modified Uncertainty Principle

There are good indications that fundamental physics gives rise to a modified space-momentum uncertainty relation that implies the existence of a minimum length scale. We implement this idea in the scalar field theory that describes density perturbations in flat Robertson-Walker space-time. This leads to a non-linear time-dependent dispersion relation that encodes the effects of Planck scale physics in the inflationary epoch. Unruh type dispersion relations naturally emerge in this approach, while unbounded ones are excluded by the minimum length principle. We also find red-shift induced modifications of the field theory, due to the reduction of degrees of freedom at high energies, that tend to dampen the fluctuations at trans-Planckian momenta. In the specific example considered, this feature helps determine the initial state of the fluctuations, leading to a flat power spectrum.Comment: LaTeX, 26 pages, 3 eps figures; (V2) Expanded version: added section 2.1, comments and references; more detailed derivation in section 4.

Generalized Second Law of Thermodynamics in f(T)f(T) Gravity with Entropy Corrections

We study the generalized second law (GSL) of thermodynamics in $f(T)$ cosmology. We consider the universe as a closed bounded system filled with $n$ component fluids in the thermal equilibrium with the cosmological boundary. We use two different cosmic horizons: the future event horizon and the apparent horizon. We show the conditions under which the GSL will be valid in specific scenarios of the quintessence and the phantom energy dominated eras. Further we associate two different entropies with the cosmological horizons: with a logarithmic correction term and a power-law correction term. We also find the conditions for the GSL to be satisfied or violated by imposing constraints on model parameters.Comment: 17 pages, no figure, title changed, version accepted for publication in Astrophysics and Space Scienc