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Lopez-Honorez, L., Mena, O., & Rigolin, S. (2012). Biases on cosmological parameters by general relativity effects. Phys. Rev. D, 85(2), 023511–12pp.
Abstract: General relativistic corrections to the galaxy power spectrum appearing at the horizon scale, if neglected, may induce biases on the measured values of the cosmological parameters. In this paper, we study the impact of general relativistic effects on non standard cosmologies such as scenarios with a time dependent dark energy equation of state, with a coupling between the dark energy and the dark matter fluids or with non-Gaussianities. We then explore whether general relativistic corrections affect future constraints on cosmological parameters in the case of a constant dark energy equation of state and of non-Gaussianities. We find that relativistic corrections on the power spectrum are not expected to affect the foreseen errors on the cosmological parameters nor to induce large biases on them.
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Boucenna, M. S., Morisi, S., Tortola, M., & Valle, J. W. F. (2012). Bilarge neutrino mixing and the Cabibbo angle. Phys. Rev. D, 86(5), 051301–4pp.
Abstract: Recent measurements of the neutrino mixing angles cast doubt on the validity of the so-far popular 2 tribimaximal mixing Ansatz. We propose a parametrization for the neutrino mixing matrix where the reactor angle seeds the large solar and atmospheric mixing angles, equal to each other in first approximation. We suggest such a bilarge mixing pattern as a model-building standard, realized when the leading order value of theta(13) equals the Cabibbo angle lambda(C).
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Olmo, G. J. (2012). Birkhoff's theorem and perturbations in f(R) theories. Ann. Phys.-Berlin, 524(5), 87–88.
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Martinez-Asencio, J., Olmo, G. J., & Rubiera-Garcia, D. (2012). Black hole formation from a null fluid in extended Palatini gravity. Phys. Rev. D, 86(10), 104010–8pp.
Abstract: We study the formation and perturbation of black holes by null fluxes of neutral matter in a quadratic extension of general relativity formulated a la Palatini. Working in a spherically symmetric space-time, we obtain an exact analytical solution for the metric that extends the usual Vaidya-type solution to this type of theory. We find that the resulting space-time is formally that of a Reissner-Nordstrom black hole but with an effective charge term carrying the wrong sign in front of it. This effective charge is directly related to the luminosity function of the radiation stream. When the ingoing flux vanishes, the charge term disappears and the space-time relaxes to that of a Schwarzschild black hole. We provide two examples that illustrate the formation of a black hole from Minkowski space and the perturbation by a finite pulse of radiation of an existing Schwarzschild black hole.
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Bodenstein, S., Bordes, J., Dominguez, C. A., Peñarrocha, J., & Schilcher, K. (2012). Bottom-quark mass from finite energy QCD sum rules. Phys. Rev. D, 85(3), 034003–5pp.
Abstract: Finite energy QCD sum rules involving both inverse-and positive-moment integration kernels are employed to determine the bottom-quark mass. The result obtained in the (MS) over bar scheme at a reference scale of 10 GeV is m (m) over bar (b)(10 GeV) = 3623(9) MeV. This value translates into a scale-invariant mass (m) over bar (b)((m) over bar (b)) = 4171(9) MeV. This result has the lowest total uncertainty of any method, and is less sensitive to a number of systematic uncertainties that affect other QCD sum rule determinations.
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