Self-Dual Conformal Supergravity and the Hamiltonian Formulation

In terms of Dirac matrices the self-dual and anti-self-dual decomposition of a conformal supergravity is given and a self-dual conformal supergravity theory is developed as a connection dynamic theory in which the basic dynamic variabes include the self-dual spin connection i.e. the Ashtekar connection rather than the triad. The Hamiltonian formulation and the constraints are obtained by using the Dirac-Bergmann algorithm. PACS numbers: 04.20.Cv, 04.20.Fy,04.65.+

Ehrenfest relations at the glass transition: solution to an old paradox

In order to find out whether there exists a thermodynamic description of the glass phase, the Ehrenfest relations along the glass transition line are reconsidered. It is explained that the one involving the compressibility is always satisfied, and that the one involving the specific heat is principally incorrect. Thermodynamical relations are presented for non-ergodic systems with a one-level tree in phase space. They are derived for a spin glass model, checked for other models, and expected to apply, e.g., to glass forming liquids. The second Ehrenfest relation gets a contribution from the configurational entropy.Comment: 4 pages revtex, to appear in Phys. Rev. Let

Dilaton and Second-Rank Tensor Fields as Supersymmetric Compensators

We formulate a supersymmetric theory in which both a dilaton and a second-rank tensor play roles of compensators. The basic off-shell multiplets are a linear multiplet (B_{\mu\nu}, \chi, \phi) and a vector multiplet (A_\mu, \l; C_{\mu\nu\rho}), where \phi and B_{\m\n} are respectively a dilaton and a second-rank tensor. The third-rank tensor C_{\mu\nu\rho} in the vector multiplet is 'dual' to the conventional D-field with 0 on-shell or 1 off-shell degree of freedom. The dilaton \phi is absorbed into one longitudinal component of A_\mu, making it massive. Initially, B_{\mu\nu} has 1 on-shell or 3 off-shell degrees of freedom, but it is absorbed into the longitudinal components of C_{\mu\nu\rho}. Eventually, C_{\mu\nu\rho} with 0 on-shell or 1 off-shell degree of freedom acquires in total 1 on-shell or 4 off-shell degrees of freedom, turning into a propagating massive field. These basic multiplets are also coupled to chiral multiplets and a supersymmetric Dirac-Born-Infeld action. Some of these results are also reformulated in superspace. The proposed mechanism may well provide a solution to the long-standing puzzle of massless dilatons and second-rank tensors in supersymmetric models inspired by string theory.Comment: 15 pages, no figure

Four dimensional R^4 superinvariants through gauge completion

We fully compute the N=1 supersymmetrization of the fourth power of the Weyl tensor in d=4 x-space with the auxiliary fields. In a previous paper, we showed that their elimination requires an infinite number of terms; we explicitely compute those terms to order \kappa^4 (three loop). We also write, in superspace notation, all the possible N=1 actions, in four dimensions, that contain pure R^4 terms (with coupling constants). We explicitely write these actions in terms of the \theta components of the chiral density \epsilon and the supergravity superfields R, G_m, W_{ABC}. Using the method of gauge completion, we compute the necessary \theta components which allow us to write these actions in x-space. We discuss under which circumstances can these extra R^4 correction terms be reabsorbed in the pure supergravity action, and their relevance to the quantum supergravity/string theory effective actions.Comment: 20 pages, no figures. Sec. 3 clarified; typos correcte

"Optical conductance fluctuations: diagrammatic analysis in Landauer approach and non-universal effects"

The optical conductance of a multiple scattering medium is the total transmitted light of a diffuse incoming beam. This quantity, very analogous to the electronic conductance, exhibits universal conductance fluctuations. We perform a detailed diagrammatic analysis of these fluctuations. With a Kadanoff-Baym technique all the leading diagrams are systematically generated. A cancellation of the short distance divergencies occurs, that yields a well behaved theory. The analytical form of the fluctuations is calculated and applied to optical systems. Absorption and internal reflections reduce the fluctuations significantly.Comment: 25 pages Revtex 3.0, 18 seperate postscript figure

On the Dirac Eigenvalues as Observables of the on-shell N=2 D=4 Euclidean Supergravity

We generalize previous works on the Dirac eigenvalues as dynamical variables of the Euclidean gravity and N=1 D=4 supergravity to on-shell N=2 D=4 Euclidean supergravity. The covariant phase space of the theory is defined as as the space of the solutions of the equations of motion modulo the on-shell gauge transformations. In this space we define the Poisson brackets and compute their value for the Dirac eigenvalues.Comment: 10 pages, LATeX fil

Green function Retrieval and Time-reversal in a Disordered World

We apply the theory of multiple wave scattering to two contemporary, related topics: imaging with diffuse correlations and stability of time-reversal of diffuse waves, using equipartition, coherent backscattering and frequency speckles as fundamental concepts.Comment: 1 figur

Gauge Fixing in Higher Derivative Gravity

Linearized four-derivative gravity with a general gauge fixing term is considered. By a Legendre transform and a suitable diagonalization procedure it is cast into a second-order equivalent form where the nature of the physical degrees of freedom, the gauge ghosts, the Weyl ghosts, and the intriguing "third ghosts", characteristic to higher-derivative theories, is made explicit. The symmetries of the theory and the structure of the compensating Faddeev-Popov ghost sector exhibit non-trivial peculiarities.Comment: 21 pages, LaTe

The Finiteness Requirement for Six-Dimensional Euclidean Einstein Gravity

The finiteness requirement for Euclidean Einstein gravity is shown to be so stringent that only the flat metric is allowed. We examine counterterms in 4D and 6D Ricci-flat manifolds from general invariance arguments.Comment: 15 pages, Introduction is improved, many figures(eps

Gravitational Properties of Monopole Spacetimes Near the Black Hole Threshold

Although nonsingular spacetimes and those containing black holes are qualitatively quite different, there are continuous families of configurations that connect the two. In this paper we use self-gravitating monopole solutions as tools for investigating the transition between these two types of spacetimes. We show how causally distinct regions emerge as the black hole limit is achieved, even though the measurements made by an external observer vary continuously. We find that near-critical solutions have a naturally defined entropy, despite the absence of a true horizon, and that this has a clear connection with the Hawking-Bekenstein entropy. We find that certain classes of near-critical solutions display naked black hole behavior, although they are not truly black holes at all. Finally, we present a numerical simulation illustrating how an incident pulse of matter can induce the dynamical collapse of a monopole into an extremal black hole. We discuss the implications of this process for the third law of black hole thermodynamics.Comment: 23 pages, 4 figures RevTe