Modern Physics Letters A

We present a semi-analytic exploration of some low-$\ell$ angular power spectra inspired by “brane supersymmetry breaking (BSB)”. This mechanism splits Bose and Fermi excitations in string theory, leaving behind an exponential potential that is just too steep for the inflaton to emerge from the initial singularity while descending it. As a result, the scalar generically bounces against the exponential wall, which typically introduces an infrared depression and a pre-inflationary peak in the power spectrum of scalar perturbations. We elaborate on a possible link between this phenomenon and the low-$\ell$ CMB. For the first 32 multipoles, combining the hard exponential with a milder one leading to $n_s\simeq 0.96$ and with a small Gaussian bump, we have attained a reduction of ${\chi }^2$ to about 46% of the standard ΛCDM setting, with both WMAP9 and PLANCK 2013 data. This result corresponds to a ${\chi }^2∕DOF$ of about 0.45, to be compared with a ΛCDM value of about 0.85. The preferred choices combine naturally quadrupole depression, a first peak around $\ell =5$ and a wide minimum around $\ell =20$. We have also gathered some evidence that similar spectra emerge if the hard exponential is combined with more realistic models of inflation. A problem of the preferred examples is their slow convergence to an almost scale-invariant profile.

We discuss mass matrices with four texture zeros for the quarks and leptons. The three mixing angles for the quarks and leptons are functions of the fermion masses. The results agree with the experimental data. The ratio of the masses of the first two neutrinos is given by the solar mixing angle. The neutrino masses are calculated: $m_1\approx 0.004\mathrm{\text{eV}}$, $m_2\approx 0.010\mathrm{\text{eV}}$ and $m_3\approx 0.070\mathrm{\text{eV}}$.

Counting galaxy number density with wide range sky surveys has been well adopted in researches focusing on revealing evolution pattern of different types of galaxies. As understood intuitively the astrophysics environment physics is intimately affected by cosmology priors with theoretical estimation or vice versa, or simply stating that the astrophysics effect couples the corresponding cosmology observations or the way backwards. In this paper, we try to quantify the influence on galaxy number density prediction at faint luminosity limit from the uncertainties in cosmology, and how much the uncertainties blur the detection of galaxy evolution, with the hope that this trying may indeed help for precise and physical cosmology study in near future or vice versa.

The ADHM construction of instantons on four-sphere is extended to hyperbolic four-space of constant negative curvature.

In this paper, we study noncommutative static spherically symmetric wormhole solutions in the context of modified Gauss–Bonnet gravity. We explore these solutions either by assuming a viable $f(G)$ model to construct shape function or by specifying the shape function to deduce $f(G)$ model. The energy conditions are discussed for both types of wormholes. In the first case, we find a physically acceptable wormhole solution threaded by normal matter for all values of radial coordinate $r$ while the second case gives physical solution only for large values of $r$.

In this paper, we derive new modes for massive Dirac field in the background of a higher-dimensional Schwarzschild black hole. We use in our approach the Cartesian gauge defined in local frames. We work in the context of Arkani-Hamed, Dimopoulos and Dvali (ADD)-like theories, assuming that the Standard Model fields (fermions and bosons) live only on a (3+1)-dimensional brane and the extra dimensions of space can be large in size.