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Enrique F. Moreno

Publications and source records attributed to Enrique F. Moreno.

10 recordsLinked to original sources

Dualities and models in various dimensions

Working within the path-integral framework we first establish a duality between the partion functions of two $U(1)$ gauge theories with a theta term in $d=4$ space-time dimensions. Then, after a dimensional reduction to $d=3$ dimensions we arrive to the partition function of a $U(1)$ gauge theory coupled to a scalar field with an action that exhibits a Dirac monopole solution. A subsequent reduction to $d=2$ dimensions leads to the partition function of a theory in which the gauge field decouples from two scalars which have non-trivial vortex-like solutions. Finally this $d=2$ partition function can be related to the bosonized version of the two-dimensional QED$_2$ (Schwinger) model.

hep-th

Bosonization of fermions coupled to topologically massive gravity

We establish a duality between massive fermions coupled to topologically massive gravity (TGM) in $d=3$ space-time dimensions and a purely gravity theory which also will turn out to be a TGM theory but with different parameters: the original graviton mass in the TGM theory coupled to fermions picks-up a contribution from fermion bosonization. We obtain explicit bosonization rules for the fermionic currents and for the energy-momentum-tensor showing that the identifications do not depend explicitly on the parameters of the theory. These results are the gravitational analog of the results for $2+1$ Abelian and non-Abelian bosonization in flat space-time.

hep-th

Q-boson coherent states and para-Grassmann variables for multi-particle states

We describe coherent states and associated generalized Grassmann variables for a system of $m$ independent $q$-boson modes. A resolution of unity in terms of generalized Berezin integrals leads to generalized Grassmann symbolic calculus. Formulae for operator traces are given and the thermodynamic partition function for a system of $q$-boson oscillators is discussed.

math-ph

Fermions in an AdS3 Black Hole Background and the Gauge-Gravity Duality

We study a model whose dynamics is determined by a Maxwell Lagrangian coupled to a complex scalar and a Dirac fermion field, in an $AdS_3$ black hole background. Our study is performed within the context of the Euclidean formalism, in terms of an effective action $S^{eff}$ that results from integrating out the fermion field. In particular, $S^{eff}$ includes an induced parity breaking part which reduces, in the weak coupling limit, to Chern-Simons terms for both the gauge and spin connections, with temperature dependent coefficients. We find numerically the effective action minimum and, applying the AdS/CFT correspondence, we discuss the properties of the dual quantum field theory defined on the boundary. We show that, in contrast with what happens in the absence of fermions, the system does not undergo a phase transition at any finite temperature.

hep-th

A Note on Holography and Phase Transitions

Focusing on the connection between the Landau theory of second order phase transitions and the holographic approach to critical phenomena, we study diverse field theories in an anti-de Sitter black hole background. Through simple analytical approximations, solutions to the equations of motion can be obtained in closed form which give rather good approximations of the results obtained using more involved numerical methods. The agreement we find stems from rather elementary considerations on perturbation of Schrödinger equations.

hep-th

Holography and $AdS_4$ self-gravitating dyons

We present a self-gravitating dyon solution of the Einstein-Yang-Mills-Higgs equations of motion in asymptotically AdS space. The back reaction of gauge and Higgs fields on the space-time geometry leads to the metric of an asymptotically AdS black hole. Using the gauge/gravity correspondence we analyze relevant properties of the finite temperature quantum field theory defined on the boundary. In particular we identify an order operator, characterize a phase transition of the dual theory on the border and also compute the expectation value of the finite temperature Wilson loop.

hep-th

Para-Grassmann Variables and Coherent States

The definitions of para-Grassmann variables and q-oscillator algebras are recalled. Some new properties are given. We then introduce appropriate coherent states as well as their dual states. This allows us to obtain a formula for the trace of a operator expressed as a function of the creation and annihilation operators.

hep-th

Quasiparticle operators with non-Abelian braiding statistics

We study the gauge invariant fermions in the fermion coset representation of $SU(N)_k$ Wess-Zumino-Witten models which create, by construction, the physical excitations (quasiparticles) of the theory. We show that they provide an explicit holomorphic factorization of $SU(N)_k$ Wess-Zumino-Witten primaries and satisfy non-Abelian braiding relations.

hep-th

Coset Models in Monopole Backgrounds

We study a fermionic coset model $G/H$ when the subgroup $H$ is not simply connected. We show that even when the fermionic zero modes impose selection rules which alters the values of the correlators, the Virasoro central charge of the theory results independent of the topological sector.

hep-th

Functional determinant and Green functions for a fermionic gauge theory on the disk

We study a theory of Dirac fermions on a disk in presence of an electromagnetic field. Using the heat-kernel technique we compute the functional determinant which results after decoupling the zero-flux gauge degrees of freedom from the fermions. We also compute the Green functions of the remaining fermionic theory with the appropriate boundary conditions. Finally we analyze the coset model associated to this gauge theory and compute all its correlations functions.

hep-th