Higher Equations of Motion in Boundary Liouville Field Theory

In addition to the ordinary bulk higher equations of motion in the boundary version of the Liouville conformal field theory, an infinite set of relations containing the boundary operators is found. These equations are in one-to-one correspondence with the singular representations of the Virasoro algebra. We comment on the possible applications in the context of minimal boundary Liouville gravity.Comment: 18 page

The Cosmic Microwave Background and Particle Physics

In forthcoming years, connections between cosmology and particle physics will be made increasingly important with the advent of a new generation of cosmic microwave background (CMB) experiments. Here, we review a number of these links. Our primary focus is on new CMB tests of inflation. We explain how the inflationary predictions for the geometry of the Universe and primordial density perturbations will be tested by CMB temperature fluctuations, and how the gravitational waves predicted by inflation can be pursued with the CMB polarization. The CMB signatures of topological defects and primordial magnetic fields from cosmological phase transitions are also discussed. Furthermore, we review current and future CMB constraints on various types of dark matter (e.g. massive neutrinos, weakly interacting massive particles, axions, vacuum energy), decaying particles, the baryon asymmetry of the Universe, ultra-high-energy cosmic rays, exotic cosmological topologies, and other new physics.Comment: 43 pages. To appear in Annual Reviews of Nuclear and Particle Scienc

Warped Radion Dark Matter

Warped scenarios offer an appealing solution to the hierarchy problem. We consider a non-trivial deformation of the basic Randall-Sundrum framework that has a KK-parity symmetry. This leads to a stable particle beyond the Standard Model, that is generically expected to be the first KK-parity odd excitation of the radion field. We consider the viability of the KK-radion as a DM candidate in the context of thermal and non-thermal production in the early universe. In the thermal case, the KK-radion can account for the observed DM density when the radion decay constant is in the natural multi-TeV range. We also explore the effects of coannihilations with the first KK excitation of the RH top, as well as the effects of radion-Higgs mixing, which imply mixing between the KK-radion and a KK-Higgs (both being KK-parity odd). The non-thermal scenario, with a high radion decay constant, can also lead to a viable scenario provided the reheat temperature and the radion decay constant take appropriate values, although the reheat temperature should not be much higher than the TeV scale. Direct detection is found to be feasible if the DM has a small (KK-parity odd) Higgs admixture. Indirect detection via a photon signal from the galactic center is an interesting possibility, while the positron and neutrino fluxes from KK-radion annihilations are expected to be rather small. Colliders can probe characteristic aspects of the DM sector of warped scenarios with KK-parity, such as the degeneracy between the radion and the KK-radion (DM) modes.Comment: 43 pages, 16 figures; added reference

Mobile annotation of geo-locations in digital books

This demo paper introduces an editor for manual annotation of locations in digital books, using a crowd-sourcing approach. It is the first of its kind and allows book lovers and literary travel enthusiasts to annotate the locations in their digital books on-the-go. We show both a mobile and a desktop version, and briefly explain the linkage to the Digital Library that is holding the digital books

On BCFW shifts of integrands and integrals

In this article a first step is made towards the extension of Britto-Cachazo-Feng-Witten (BCFW) tree level on-shell recursion relations to integrands and integrals of scattering amplitudes to arbitrary loop order. Surprisingly, it is shown that the large BCFW shift limit of the integrands has the same structure as the corresponding tree level amplitude in any minimally coupled Yang-Mills theory in four or more dimensions. This implies that these integrands can be reconstructed from a subset of their `single cuts'. The main tool is powercounting Feynman graphs in a special lightcone gauge choice employed earlier at tree level by Arkani-Hamed and Kaplan. The relation between shifts of integrands and shifts of its integrals is investigated explicitly at one loop. Two particular sources of discrepancy between the integral and integrand are identified related to UV and IR divergences. This is cross-checked with known results for helicity equal amplitudes at one loop. The nature of the on-shell residue at each of the single-cut singularities of the integrand is commented upon. Several natural conjectures and opportunities for further research present themselves.Comment: 43 pages, 6 figures, v2: minor improvement in exposition, typos fixed, bibliography update

Aidnogenesis via Leptogenesis and Dark Sphalerons

We discuss aidnogenesis, the generation of a dark matter asymmetry via new sphaleron processes associated to an extra non-abelian gauge symmetry common to both the visible and the dark sectors. Such a theory can naturally produce an abundance of asymmetric dark matter which is of the same size as the lepton and baryon asymmetries, as suggested by the similar sizes of the observed baryonic and dark matter energy content, and provide a definite prediction for the mass of the dark matter particle. We discuss in detail a minimal realization in which the Standard Model is only extended by dark matter fermions which form "dark baryons" through an SU(3) interaction, and a (broken) horizontal symmetry that induces the new sphalerons. The dark matter mass is predicted to be approximately 6 GeV, close to the region favored by DAMA and CoGeNT. Furthermore, a remnant of the horizontal symmetry should be broken at a lower scale and can also explain the Tevatron dimuon anomaly.Comment: Minor changes, discussion of present constraints expanded. 16 pages, 2 eps figures, REVTeX

Doping the holographic Mott insulator

Mott insulators form because of strong electron repulsions, being at the heart of strongly correlated electron physics. Conventionally these are understood as classical "traffic jams" of electrons described by a short-ranged entangled product ground state. Exploiting the holographic duality, which maps the physics of densely entangled matter onto gravitational black hole physics, we show how Mott-insulators can be constructed departing from entangled non-Fermi liquid metallic states, such as the strange metals found in cuprate superconductors. These "entangled Mott insulators" have traits in common with the "classical" Mott insulators, such as the formation of Mott gap in the optical conductivity, super-exchange-like interactions, and form "stripes" when doped. They also exhibit new properties: the ordering wave vectors are detached from the number of electrons in the unit cell, and the DC resistivity diverges algebraically instead of exponentially as function of temperature. These results may shed light on the mysterious ordering phenomena observed in underdoped cuprates.Comment: 27 pages, 9 figures. Accepted in Nature Physic

TOPOLOGICAL DEFECTS AND HIGHEST ENERGY COSMIC AND GAMMA RAYS

In this paper we review the hypothesis that a considerable part of the cosmic ray flux observed above about 10^{19}\eV may be produced by decaying or annihilating topological defects left over from phase transitions in the early universe at grand unification energy scales (\approx10^{16}\GeV). Possible signatures of cosmic ray producing defect models are discussed which could be tested experimentally in the near future. We thereby focus on model independent universal spectral properties of the predicted particle fluxes.Comment: 11 pages of uuencoded compressed postscript, including 3 figures, to be published in Space Science Reviews

The Cosmological Constant

This is a review of the physics and cosmology of the cosmological constant. Focusing on recent developments, I present a pedagogical overview of cosmology in the presence of a cosmological constant, observational constraints on its magnitude, and the physics of a small (and potentially nonzero) vacuum energy.Comment: 50 pages. Submitted to Living Reviews in Relativity (http://www.livingreviews.org/), December 199

On Stability and Transport of Cold Holographic Matter

We use gauge-gravity duality to study the stability of zero-temperature, finite baryon density states of N=4 supersymmetric SU(Nc) Yang-Mills theory coupled to a single massive fundamental-representation N=2 hypermultiplet in the large-Nc and large-coupling limits. In particular, we study the spectrum of mesons. The dual description is a probe D7-brane in anti-de Sitter space with a particular configuration of worldvolume fields. The meson spectrum is dual to the spectrum of fluctuations of worldvolume fields about that configuration. We use a combination of analytical and numerical techniques to compute the spectrum, including a special numerical technique designed to deal with singular points in the fluctuations' equations of motion. Despite circumstantial evidence that the system might be unstable, such as a finite entropy density at zero temperature and the existence of instabilities in similar theories, we find no evidence of any instabilities, at least for the ranges of frequency and momenta that we consider. We discover a pole on the imaginary frequency axis in a scalar meson two-point function, similar to the diffusive mode in the two-point function of a conserved charge.Comment: 40 pages, 7 figure