Interacting Dark Energy and Dark Matter is used to go beyond the standard cosmology. We base our arguments on Planck data and conclude that an interaction is compatible with the observations and can provide a strong argument towards consistency of different values of cosmological parameters.PACS numbers: 98.80. Es, 98.80.Jk, 95.30.Sf

Abstract. We investigate phenomenological interactions between dark matter and dark energy and constrain these models by employing the most recent cosmological data including the cosmic microwave background radiation anisotropies from Planck 2015, Type Ia supernovae, baryon acoustic oscillations, the Hubble constant and redshift-space distortions. We find that the interaction in the dark sector parameterized as an energy transfer from dark matter to dark energy is strongly suppressed by the whole updated cosmological data. On the other hand, an interaction between dark sectors with the energy flow from dark energy to dark matter is proved in better agreement with the available cosmological observations. This coupling between dark sectors is needed to alleviate the coincidence problem.

The result presented by the BOSS-SDSS Collaboration measuring the baryon acoustic oscillations of the Lyman-alpha forest from high-redshift quasars indicates a 2.5σ departure from the standard Λ-cold-dark-matter model. This is the first time that the evolution of dark energy at high redshifts has been measured, and the current results cannot be explained by simple generalizations of the cosmological constant. We show here that a simple phenomenological interaction in the dark sector provides a good explanation for this deviation, naturally accommodating the Hubble parameter obtained by BOSS, H(z = 2.34) = 222 ± 7 km s −1 Mpc −1 . By performing a global fit of the parameters with the inclusion of this new data set together with the Planck data for the interacting model, we are able to show that some interacting models have constraints for H(2.34) and DA(2.34) that are compatible with the ones obtained by the BOSS Collaboration, showing a better concordance than ΛCDM. We also show that the interacting models that have a small positive coupling constant, which helps alleviate the coincidence problem, are compatible with the cosmological observations. Adding the likelihood of these new baryon acoustic oscillations data shows an improvement in the global fit, although it is not statistically significant. The coupling constant could not be fully constrained by the data sets used, but the dark energy equation of state shows a slight preference for a value different from a cosmological constant.PACS numbers: 95.36.+x, 98.80.Es, 95.30.Sf, 98.80.Jk

We present results from the first directed search for nontensorial gravitational waves. While general relativity allows for tensorial (plus and cross) modes only, a generic metric theory may, in principle, predict waves with up to six different polarizations. This analysis is sensitive to continuous signals of scalar, vector, or tensor polarizations, and does not rely on any specific theory of gravity. After searching data from the first observation run of the advanced LIGO detectors for signals at twice the rotational frequency of 200 known pulsars, we find no evidence of gravitational waves of any polarization. We report the first upper limits for scalar and vector strains, finding values comparable in magnitude to previously published limits for tensor strain. Our results may be translated into constraints on specific alternative theories of gravity.

This work deals with the influence of the gravitational field produced by a charged and rotating black hole (Kerr-Newman spacetime) on massive scalar fields. We obtain an exact solution of the Klein-Gordon equation in this spacetime, which is given in terms of the confluent Heun functions. In the particular case corresponding to an extreme Kerr-Newman black hole the solution is given by the double confluent Heun functions. We also investigate the solutions in regions near the event horizon and far from the black hole.PACS numbers: 04.20.Jb, 04.70.Dy, 02.30.Gp of the Klein-Gordon equation in some gravitational fields as well as their consequences have been discussed in the literature [1,2,3,4,5,6,7,8,9,10,11,12].By the middle of 70's of last century, Rowan and Stephenson [5], solved the Klein-Gordon equation for a massive field in the Kerr-Newman spacetime. The obtained solutions are not valid for the whole spacetime, but only near the exterior horizon and at infinity, and are given in terms of Whittaker functions.Solutions to the Klein-Gordon equation for a charged massive scalar field in the Kerr-Newman spacetime were obtained by Wu and Cai [9]. They showed that the radial and angular equations correspond to a generalized spin-weighted spheroidal wave functions, in the non-extreme case. In this context, the general solutions in integral forms and in power series expansion were obtained and the appropriate forms of the equations suitable to study some problems of physical interest, as the ones concerning black hole evaporation, black hole radiation and scattering states, among others, were presented and their solutions given. In the extreme case, the solutions of the radial equation were written in power series expansion and some discussion presented.Another paper by Furuhashi and Nambu [13] presents solutions of the Klein-Gordon equation for a massive scalar field in Kerr-Newman spacetime. The solutions were considered very far from the exterior event horizon and near the black hole event horizon. In the first case, it was found that the solutions regular at infinity is given in terms of the confluent hypergeometric functions, and in the opposite situation, namelly, near the horizon, the solution is given in terms of the Gauss hypergeometric function. Therefore, the obtained solutions are valid in a restricted ranges.In our paper we obtain the exact solutions of the Klein-Gordon equation in the background under consideration, valid in the whole space which corresponds to the black hole exterior which means between the event horizon and infinity. In this sense, we extend the range in which the solutions are valid as compared with the ones obtained by Rowan and Stephenson [5]. They are given in terms of solutions of the Heun equations [14]. We also analyze the asymptotic behavior of the solutions and compared with the corresponding ones obtained by Rowan and Stephenson [5]. The solution of the Klein-Gordon equation for the extreme Kerr-Newman black hole is also obtained and is given by the double confluent Heun fu...