Jose Navarro-Salas

Modeling black hole evaporation

Classical Black Holes The Hawking Effect Near-Horizon Approximation and Conformal Symmetry Stress Tensor, Anomalies and Effective Actions Models for Evaporating Black Holes.

AdS(2) / CFT(1) correspondence and near extremal black hole entropy

Abstract We provide a realization of the AdS 2 /CFT 1 correspondence in terms of asymptotic symmetries of the AdS 2 × S 1 and AdS 2 × S 2 geometries arising in near-extremal BTZ and Reissner–Nordstrom black holes. We evaluate the corresponding central charges and show that Cardys formula exactly accounts for the deviation of the Bekenstein–Hawking entropy from extremality. We also argue that this result can be extended to more general black holes near extremality.

Algebraic quantization on a group and nonabelian constraints

A generalization of a previous group manifold quantization formalism is proposed. In the new version the differential structure is circumvented, so that discrete transformations in the group are allowed, and a nonabelian group replaces the ordinary (central)U(1) subgroup of the Heisenberg-Weyl-like quantum group. As an example of the former we obtain the wave functions associated with the system of two identical particles, and the latter modification is used to account for the Virasoro constraints in string theory.

A note on Einstein gravity on AdS3 and boundary conformal field theory

Abstract We find a simple relation between the first subleading terms in the asymptotic expansion of the metric field in AdS3, obeying the Brown-Henneaux boundary conditions, and the stress tensor of the underlying Liouville theory on the boundary. We can also provide an more explicit relation between the bulk metric and the boundary conformal field theory when it is described in terms of a free field with a background charge.We find a simple relation between the first subleading terms in the asymptotic expansion of the metric field in AdS 3 , obeying the Brown-Henneaux boundary conditions, and the stress tensor of the underlying Liouville theory on the boundary. We can also provide an more explicit relation between the bulk metric and the boundary conformal field theory when it is described in terms of a free field with a background charge.

Revising the predictions of inflation for the cosmic microwave background anisotropies

We point out that, if quantum field renormalization is taken into account and the counterterms are evaluated at the Hubble-radius crossing time or few e-foldings after it, the predictions of slow-roll inflation for both the scalar and the tensorial power spectrum change significantly. This leads to a change in the consistency condition that relates the tensor-to-scalar amplitude ratio with spectral indices. A reexamination of the potentials varphi;{2} and varphi;{4} shows that both are compatible with five-year WMAP data. Only when the counterterms are evaluated at much larger times beyond the end of inflation does one recover the standard predictions. The alternative predictions presented here may soon come within the range of measurement of near-future experiments.

Quantization on the Virasoro Group

The quantization of the Virasoro group is carried out by means of a previously established group approach to quantization. We explicitly work out the two-cocycles on the Virasoro group as a preliminary step. In our scheme the carrier space for all the Virasoro representations is made out of polarized functions on the group manifold. It is proved that this space does not contain null vector states, even forc≦1, although it is not irreducible. The full reduction is achieved in a striaghtforward way by just taking a well defined invariant subspace ℋ(c, h), the orbit of the enveloping algebra through the vacuum, which is irreducible for any value ofc andh. ℋ(c, h) is a proper subspace of the space of polarized functions for those values ofc andh for which the Kac determinant is zero. We give the local version of these group representations as well as the associated classical phase space structures, i.e., symplectic form and Noether invariants.

Formal Group Laws for Affine Kac-Moody groups and group quantization

We describe a method for obtaining Formal Group Laws from the structure constants of Affine Kac-Moody groups and then apply a group manifold quantization procedure which permits construction of physical representations by using only canonical structures on the group. As an intermediate step we get an explicit expression for two-cocycles on Loop Groups. The programme is applied to the AffineSU(2) group.

Symmetry and quantization: Higher-order polarization and anomalies

The concept of (full) polarization subalgebra in a Group Approach to Quantization on a Lie group G as a generalization of the analogous concept in geometric or standard quantization is discussed. The lack of full polarization subalgebras is considered as an anomaly of the corresponding system and related to its more conventional definition. A generalization of the subalgebra of (full) polarization is then provided, made out of higher‐order differential operators in the enveloping algebra of G. Higher‐order polarizations can also be used to quantize nonanomalous theories in different ‘‘representations.’’ Numerous examples are analyzed, including the finite‐dimensional dynamics associated with the Schrodinger group, which presents an anomaly, and an infinite‐dimensional anomalous system associated with the Virasoro group. In the last example, the operators in the higher‐order polarization are in one‐to‐one correspondence with the null vectors in the Verma module approach.

Revising the observable consequences of slow-roll inflation

This work has been partially supported by the spanish grant FIS2008-06078-C03-02. I.A. and L.P. have been partly supported by NSF grants PHY- 0071044 and PHY-0503366 and by a UWM RGI grant. G.O. thanks MICINN for a JdC contract and the “Jose Castillejo” program for funding a stay at the University of Wisconsin-Milwaukee. We thank D. Lyth for interesting correspondence. We also thank R. Durrer, G. Marozzi, and M. Rinaldi for a private communication about their views on our results in [7].

Group-theoretical construction of the quantum relativistic harmonic oscillator☆

We elaborate on a proposal for a quantum relativistic harmonic oscillator, based on a group-theoretical framework. The wave functions in both configuration and Bargmann-Fock-like space are explicitly given and a generalized Bargmann transform is also provided. The energy eigen-functions in configuration space are composed of a general weight function (the vacuum), which leads to the Gaussian one in the c → ∞ limit, a particular power of the vacuum reducing to unity in this limit and a polynomial leading to the corresponding non-relativistic Hermite polynomial as c → ∞.