Adrian R. Lugo

Monopole and dyon solutions in AdS space

Abstract We consider monopole and dyon classical solutions of the Yang-Mills-Higgs system coupled to gravity in asymptotically anti-de Sitter space. We discuss both singular and regular solutions to the second order equations of motion showing that singular Wu-Yang like dyons can be found, the resulting metric being of the Reissner-Nordstrom type (with cosmological constant). Concerning regular solutions, we analyze the conditions under which they can be constructed discussing, for vanishing coupling constant, the main distinctive features related to the anti-de Sitter asymptotic condition; in particular, we find in this case that the v.e.v. of the Higgs scalar, | H (∞)| , should be quantized in units of the natural mass scale 1/e r 0 (related to the cosmological constant) according to | H (∞)| 2 =m(m+1)(e r 0 ) −2 , with m ∈ Z .

Monopole solutions in AdS space

Abstract We find monopole solutions for a spontaneously broken SU (2)-Higgs system coupled to gravity in asymptotically anti-de Sitter space. We present new analytic and numerical results discussing, in particular, how the gravitational instability of self-gravitating monopoles depends on the value of the cosmological constant.We find monopole solutions for a spontaneously broken SU(2)-Higgs system coupled to gravity in asymptotically anti-de Sitter space. We present new analytic and numerical results discussing,in particular, how the gravitational instability of self-gravitating monopoles depends on the value of the cosmological constant.

A numerical study of lattice QED with dynamical fermions

Abstract Using the pseudo-fermion method U(1) lattice gauge theory with dynamical staggered fermions is studied. The plaqette energy, the chiral order parameter and the Polyakov line have been measured. With fermions of mass 0.20 and 0.25 a phase transition is observed, separating the strong coupling regime from a phase where chiral symmetry is restored.

Supertubes and special holonomy

Abstract We obtain a (1/4)-supersymmetric 6-brane solution of IIA supergravity by T-dualizing the supertube recently found. The resulting C1 electric charge is related to the original D0-brane charge. The uplifted solution to eleven dimensions results to be a purely geometrical configuration, which can be interpreted as a bound state of a Taub-NUT space and a pp-wave. Being the non-trivial part of the metric pseudo-Riemannian, the resulting reduced holonomy group is non-compact and locally isomorphic to a semidirect product of an Abelian four-dimensional group and SU(2).

On the matching method and the Goldstone theorem in holography

A bstractWe study the transition of a scalar field in a fixed AdSd+1 background between an extremum and a minimum of a potential. We compute analytically the solution to the perturbation equation for the vev deformation case by generalizing the usual matching method to higher orders and find the propagator of the boundary theory operator defined through the AdS-CFT correspondence. We show that, contrary to what happens at the leading order of the matching method, the next-to-leading order presents a simple pole at q2 = 0 in accordance with the Goldstone theorem applied to a spontaneously broken dilatation invariance.

Holographic phase transition from dyons in an AdS black hole background

We construct a dyon solution for a Yang-Mills-Higgs theory in a 4 dimensional Schwarzschild-anti-de Sitter black hole background with temperature T. We then apply the AdS/CFT correspondence to describe the strong coupling regime of a 2 + 1 quantum field theory which undergoes a phase transition exhibiting the condensation of a composite charge operator below a critical temperature Tc.

On supersymmetric Dp-Dp brane solutions

Abstract We analyze in the spirit of hep-th/0110039 the possible existence of supersymmetric Dp– D p brane systems in flat ten-dimensional Minkowski space. For p=3,4 we show that besides the solutions related by T-duality to the D2– D 2 systems found by Bak and Karch there exist other ansatz whose compatibility is shown from general arguments and that preserve also eight supercharges, in particular, a D4– D 4 system with D2-branes dissolved on it and Taub–NUT charge. We carry out the explicit construction in Weyl basis of the corresponding Killing spinors and conjecture the existence of new solutions for higher-dimensional branes with some compact directions analogous to the supertube recently found.

Holographic phase transitions from higgsed, non abelian charged black holes

A bstractWe find solutions of a gravity-Yang-Mills-Higgs theory in four dimensions that represent asymptotic anti-de Sitter charged black holes with partial/full gauge symme-try breaking. We then apply the AdS/CFT correspondence to study the strong coupling regime of a 2 + 1 quantum field theory at temperature T and finite chemical potential, which undergoes transitions to phases exhibiting the condensation of a composite charged vector operator below a critical temperature Tc, presumably describing p + ip/p-wave su-perconductors. In the case of p + ip-wave superconductors the transitions are always of second order. But for p-wave superconductors we determine the existence of a critical value αc of the gravitational coupling (for fixed Higgs v.e.v. parameter m^W

A NOTE ON NONCOMMUTATIVE CHERN–SIMONS MODEL ON MANIFOLDS WITH BOUNDARY

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