We consider the Casimir energy due to a massless scalar field in a geometryof an infinite wedge closed by a Dirichlet circular cylinder, where the wedgeis formed by $\delta$-function potentials, so-called semitransparentboundaries. A finite expression for the Casimir energy corresponding

We consider a self-consistent Einstein-Maxwell-Kalb-Ramond system in the bulkD=4 space-time interacting with a variable-tension electrically chargedlightlike brane. The latter serves both as a material and charge source forgravity and electromagnetism, as well as it dynamically generates a bulk spacevarying cosmological

We study the generation of primordial perturbations in a (single-field)slow-roll inflationary universe. In momentum space, these (Gaussian)perturbations are characterized by a zero mean and a non-zero variance$\Delta^2(k, t)$. However, in position space the variance diverges in theultraviolet. The requirement of

According to the Alday-Maldacena program the strong coupling limit of SuperYang-Mills scattering amplitudes is given by minimal area surfaces in AdSspacetime with a boundary consisting of a momentum space polygon. The stringequations in AdS systematically reduce to coupled Toda type

In this paper we will present very recent results obtained in the ambit ofquantum electrodynamics in curved spacetime. We utilize a newly developednon-perturbative heat kernel asymptotic expansion on homogeneous Abelianbundles over Riemannian manifolds in order to compute the one-loop effectiveaction

We investigate the properties of the path integral over reparametrizations (=the boundary value of the Liouville field in open string theory). Discretizingthe path integral, we apply the Metropolis-Hastings algorithm to numericalsimulations of a proper (subordinator) stochastic process and find that

We discuss the hypothesis of a fixed point for quantum gravity coupled to ascalar, in the limit where the scalar field goes to infinity, accompanied by asuitable scaling of the metric. We propose that no scalar potential is presentfor the

We provide a calculation of N-body (N>2) nucleon interactions at shortdistances in holographic QCD. In the Sakai-Sugimoto model of large N_c masslessQCD, N baryons are described by N Yang-Mills instantons in 5 spacetimedimensions. We compute a classical short distance interaction

Using the AKSZ prescription we construct 2D and 3D topological field theoriesassociated to generalized complex manifolds. These models can be thought of as2D and 3D generalizations of A- and B-models. Within the BV framework we showthat the 3D model on

The problem of computing the anomalous dimensions of a class of (nearly)half-BPS operators with a large R-charge is reduced to the problem ofdiagonalizing a Cuntz oscillator chain. Due to the large dimension of theoperators we consider, non-planar corrections must be

We analyze the five-dimensional AdS gravity coupled to a gauge field and acharged scalar field. Under a Scherk-Schwarz compactification, we show that thesystem undergoes a superconductor/insulator transition at zero temperature in2+1 dimensions as we change the chemical potential. By taking

We consider a black hole solution with a non-trivial dilaton from IIB supergravity which is expected to describe a strongly coupled hot gauge plasma withnon-vanishing gluon condensation present. We construct a rotating and movingbaryon to probe the screening and phases

We investigate the primordial non-Gaussianities from the trispectra inmulti-field inflation models, which can be seen as generalization ofmulti-field $k$-inflation and multi-DBI inflation. We derive the fullfourth-order perturbation action for the inflaton fields and evaluate thefour-point correlation functions for the perturbations

We construct the ghost number 9 three strings vertex for OSFT in the naturalnormal ordering. We find two versions, one with a ghost insertion at z=i and atwist-conjugate one with insertion at z=-i. For this reason we call themmidpoint vertices.

After having defined a 3-strings midpoint-inserted vertex for the bc system,we analyze the relation between gh=0 states (wedge states) and gh=3 midpointduals. We find explicit and regular relations connecting the two objects. Inthe case of wedge states this allows us

We argue that a selfconsistent spatial coarse-graining, which involvesinteracting (anti)calorons of unit topological charge modulus, implies thatreal-time loop expansions of thermodynamical quantities in the deconfiningphase of SU(2) and SU(3) Yang-Mills thermodynamics are, modulo 1PIresummations, determined by a finite number of

We study general two-dimensional sigma-models which do not possess manifestLorentz invariance. We show how demanding that Lorentz invariance is recoveredas an emergent on-shell symmetry constrains these sigma-models. The resultingactions have an underlying group-theoretic structure and resemble Poisson-LieT-duality invariant actions. We

Vacuum polarization effects in the cosmic string background are considered.We find that a current is induced in the vacuum of the quantized massive scalarfield and that the current circulates around the string which is generalized toa $(d-2)$-brane in locally flat

The magnetogenesis scenarios triggered by the early variation of the gaugecoupling are critically analyzed. In the absence of sources, it is shown thatthe electric and magnetic power spectra can be explicitly computed by means ofelectric-magnetic duality transformations. The remnants of

We show that the ideal relativistic spinning gas at complete thermodynamicalequilibrium is a fluid with a non-vanishing spin density tensor \sigma_\mu \nu.After having obtained the expression of the local spin-dependent phase spacedensity f(x,p)_(\sigma \tau) in the Boltzmann approximation, we derive