The Pioneer's acceleration anomaly and Hubble's constant

The reported anomalous acceleration acting on the Pioneers spacecrafts could be seen as a consequence of the existence of some local curvature in light geodesics when using the coordinate speed of light in an expanding space-time. The effect is related with the non synchronous character of the underlying metric and therefore, planets closed orbits can not reveal it. It is shown that the cosmic expansion rate -the Hubble parameter H- has been indeed detected. Additionally, a relation for an existing annual term is obtained which depends on the cosine of the ecliptic latitude of the spacecraft, suggestingan heuristic analogy between the effect and Foucault's experiment - light rays playing a similar role in the expanding space than Foucault's Pendulum does while determining Earth's rotation. This statement could be seen as a benchmark for future experiments.Comment: 8 pages, LaTex, minor changes for submissio

The Pioneer's Anomalous Doppler Drift as a Berry Phase

The detected anomalous frequency drift acceleration in Pioneer's radar data finds its explanation in a Berry phase that obtains the quantum state of a photon that propagates within an expanding space-time. The clock acceleration is just the adiabatic expansion rate and an analogy between the effect and Foucault's experiment is fully suggested. In this sense, light rays play a similar role in the expanding space than Foucault's Pendulum does while determining Earth's rotation. On the other hand, one could speculate about a suitable future experiment at "laboratory" scales able to measure the local cosmological expansion rate using the procedure outlined in this paper.Comment: 7 pages, The references are now correc

Supersymmetric Cosmology and Dark Energy

Using the superfield approach we construct the n = 2 supersymmetric lagrangian for the FRW Universe with perfect fluid as matter fields. The obtained supersymmetric algebra allowed us to take the square root of the Wheeler-DeWitt equation and solve the corresponding quantum constraint. This model leads to the relation between the vacuum energy density and the energy density of the dust matter.Comment: This article is a contribution to the anniversary volume "The Problems of Modern Cosmology". On the occasion of the 50th birthday of Prof. S.D. Odintsov. Editor Prof. P.M. Lavro

Anti-self-dual gravity and supergravity from a pure connection formulation

We introduce a complex pure connection action with constraints which is diffeomorphism and gauge invariant. Taking as an internal group $SU(2)$, we obtain, from the equations of motion, anti-self-dual Einstein spaces together with the zero torsion condition thanks to Bianchi identity. By applying the same procedure, we take as internal symmetry the super group $OSp(1|2)$ and by means of the Bianchi identity and integrability conditions, the equations of motion are those that come from anti-self-dual supergravity $N=1$ with cosmological constant sector

General scalar interaction in the supersymmetric FRW model

In this work we have constructed the most general action for a set of complex homogeneous scalar supermultiplets interacting with the scale factor in the supersymmetric FRW model. It is shown, that local conformal time supersymmetry leads to the scalar fields potential, which is defined in the same combination: K\"ahler potential and superpotential as in supergravity (or effective superstring) theories. This scalar fields potential depends on arbitrary parameter $\alpha$, which is not fixed by conformal time supersymmetry.Comment: 10 pages, Latex, no figures, submitted to MPL

Extended supersymmetry for the Bianchi-type cosmological models

In this paper we propose a superfield description for all Bianchi-type cosmological models. The action is invariant under world-line local $n=4$ supersymmetry with $SU(2)_{local}XSU(2)_{global}$ internal symmetry. Due to the invariance of the action we obtain the constraints, which form a closed superalgebra of the $n=4$ supersymmetric quantum mechanics. This procedure provides the inclusion of supermatter in a sistematic way.Comment: 9 pages, accepted in Mod. Phys. Lett.

Discrete canonical analysis of three dimensional gravity with cosmological constant

We discuss the interplay between standard canonical analysis and canonical discretization in three-dimensional gravity with cosmological constant. By using the Hamiltonian analysis, we find that the continuum local symmetries of the theory are given by the on-shell space-time diffeomorphisms, which at the action level, corresponds to the Kalb-Ramond transformations. At the time of discretization, although this symmetry is explicitly broken, we prove that the theory still preserves certain gauge freedom generated by a constant curvature relation in terms of holonomies and the Gauss's law in the lattice approach.Comment: 19 pages, 1 figure. arXiv admin note: text overlap with arXiv:1310.3759, arXiv:gr-qc/0512065, arXiv:1111.1879 by other author

A semilattice structure for the set of numerical semigroups with fixed Frobenius number

We present a procedure to enumerate the whole set of numerical semigroups with a given Frobenius number F, S(F). The methodology is based on the construction of a partition of S(F) by a congruence relation. We identify exactly one irreducible and one homogeneous numerical semigroup at each class in the relation, and from those two elements we reconstruct the whole class. An alternative more efficient method is proposed based on the use of the Kunz-coordinates vectors of the elements in S(F).Comment: 11 page

Learning Generative Models of Similarity Matrices

We describe a probabilistic (generative) view of affinity matrices along with inference algorithms for a subclass of problems associated with data clustering. This probabilistic view is helpful in understanding different models and algorithms that are based on affinity functions OF the data. IN particular, we show how(greedy) inference FOR a specific probabilistic model IS equivalent TO the spectral clustering algorithm.It also provides a framework FOR developing new algorithms AND extended models. AS one CASE, we present new generative data clustering models that allow us TO infer the underlying distance measure suitable for the clustering problem at hand. These models seem to perform well in a larger class of problems for which other clustering algorithms (including spectral clustering) usually fail. Experimental evaluation was performed in a variety point data sets, showing excellent performance.Comment: Appears in Proceedings of the Nineteenth Conference on Uncertainty in Artificial Intelligence (UAI2003

The tree of irreducible numerical semigroups with fixed Frobenius number

In this paper we present a procedure to build the set of irreducible numerical semigroups with a fixed Frobenius number. The construction gives us a rooted tree structure for this set. Furthermore, by using the notion of Kunz-coordinates vector we translate the problem of finding such a tree into the problem of manipulating 0-1 vectors with as many component as the Frobenius number.Comment: 10 page