11686379
Direct reconstruction of spherical harmonics from interferometer observations of the CMB polarization
Interferometric observation of the CMB polarization can be expressed as a linear sum of spherical harmonic coefficients a±2,lm of the CMB polarization. The linear weight for a±2,lm depends on the observational configuration such as antenna pointing, baseline orientation, and spherical harmonic number l, m. Since an interferometer is sensitive over a finite range of multipoles, a±2,lm in the range can be determined by fitting a±2,lm for visibilities of various observational configurations. The formalism presented in this paper enables the determination of a±2,lm directly from spherical harmonic spaces without spherical harmonic transformation of pixellized maps. The result of its application to a simulated observation is presented with the formalism.
118530966
How accurately can we measure the hydrogen 2S->1S transition rate from the cosmological data?
Recent progress in observational cosmology, and especially the forthcoming PLANCK mission data, open new directions in so-called precision cosmology. In this paper we illustrate this statement considering the accuracy of cosmological determination of the two-quanta decay rate of 2s hydrogen atom state. We show that the PLANCK data will allow us to measure this decay rate significantly better than in the laboratory experiments.
118997460
Alfv\'en turbulence in the WMAP 5 year data and a forecast for the PLANCK
118455901
CMB data constraint on self-annihilation of dark matter particles
Recently, self‐annihilation of dark matter particles is proposed to explain the “WMAP Haze” and excess of energetic positrons and electrons in ATIC and PAMELA results. If self‐annihilation of dark matter occurs around the recombination of cosmic plasma, energy release from self‐annihilation of dark matter delays the recombination, and hence affects CMB anisotropy. By using the recent CMB data, we have investigated the self‐annihilation of dark matter particles. In this investigation, we do not find statistically significant evidence, and impose an upper bound on 〈σν〉/mϰ.The upcoming data from Planck surveyor and the Fermi Gamma‐ray telescope will allow us to break some of parameter degeneracy and improve constraints on self‐annihilation of dark matter particles.
17325286
THE GAUSS–LEGENDRE SKY PIXELIZATION FOR THE CMB POLARIZATION (GLESP-POL) ERRORS DUE TO PIXELIZATION OF THE CMB SKY
We present the development of the method for numerical analysis of polarization in the Gauss–Legendre sky pixelization (GLESP) scheme for CMB maps. This incorporation of the polarization transforms in the pixelization scheme GLESP completes the creation of our new method for numerical analysis of CMB maps. A comparison of GLESP and HEALPix calculations is done.
118613110
How to make a clean separation between CMB E and B modes with proper foreground masking
We investigate the E/B decomposition of CMB polarization on a masked sky. In real space, operators of E and B mode decomposition involve only differentials of CMB polarization. We may, therefore in principle, perform a clean E/B decomposition from incomplete sky data. Since it is impractical to apply second derivatives to observation data, we usually rely on spherical harmonic transformation and inverse transformation, instead of using real-space operators. In spherical harmonic representation, jump discontinuities in a cut sky produces Gibbs phenomenon, unless a spherical harmonic expansion is made up to an infinitely high multipole. By smoothing a foreground mask, we may suppress the Gibbs phenomenon effectively in a similar manner to apodization of a foreground mask discussed in other works. However, we incur foreground contamination by smoothing a foreground mask, because zero-value pixels in the original mask may be rendered non-zero by the smoothing process. In this work, we investigate an optimal foreground mask, which ensures proper foreground masking and suppresses Gibbs phenomenon. We apply our method to a simulated map of the pixel resolution comparable to the Planck satellite. The simulation shows that the leakage power is lower than unlensed CMB B mode power spectrum of tensor-to-scalar ratio r ∼ 1 × 10 −7 . We compare the result with that of the original mask. We find that the leakage power is reduced by a factor of 10 6 ∼ 10 9 at the cost of a sky fraction 0.07, and that that the enhancement is highest at lowest multipoles. We confirm that all the zero-value pixels in the original mask remain zero in our mask. The application of this method to the Planck data will improve the detectability of primordial tensor perturbation.
121882543
Conditions for Natural Suppression of CP Violation
121311744
Polarization of recoil-electron beam in high-energy Moller and Bhabha scattering
Longitudinal and transverse polarizations of the final electron beam in Moller and Bhabha scattering are analyzed in electroweak gauge models involving more than one neutral vector boson. In pure QED, for given initial polarizations of incoming particles, the polarization of the outgoing electron beam is the same for Moller and Bhabha scattering and is energy independent. However, in various electroweak gauge models, we find that the energy dependence and final-state polarizations are in general different for the two scattering processes; thus, observing polarization effects in such scattering processes may be useful to test various gauge models at high energy.
53370252
Positroid stratification of orthogonal Grassmannian and ABJM amplitudes
A bstractA novel understanding of scattering amplitudes in terms of on-shell diagrams and positive Grassmannian has been recently established for four dimensional Yang-Mills theories and three dimensional Chern-Simons theories of ABJM type. We give a detailed construction of the positroid stratification of orthogonal Grassmannian relevant for ABJM amplitudes. On-shell diagrams are classified by pairing of external particles. We introduce a combinatorial aid called ‘OG tableaux’ and map each equivalence class of on-shell diagrams to a unique tableau. The on-shell diagrams related to each other through BCFW bridging are naturally grouped by the OG tableaux. Introducing suitably ordered BCFW bridges and positive coordinates, we construct the complete coordinate charts to cover the entire positive orthogonal Grassmannian for arbitrary number of external particles. The graded counting of OG tableaux suggests that the positive orthogonal Grassmannian constitutes a combinatorial polytope.
119351828
Self-tuning solution of the cosmological constant problem with antisymmetric tensor field
We obtain the self-tuning solution of the cosmological constant problem in the Randall-Sundrum model with introducing a three-index antisymmetric tensor field of a specific form in the Lagrangian. We also consider the dual description of the self-tuning solution.
118390901
The CKM matrix with maximal CP violation from Z 12 symmetry
Abstract The recent accurate determination of the CKM parameters including the maximal CP phase π 2 enables us to write down the up-type and down-type quark mass matrices to a high degree of accuracy. The lightest element ( u ¯ u element) of the quark mass texture (not the mass eigenvalue) has a power λ 6 where λ = sin θ C . The CP phase of 2 π divided by an integer hints a discrete symmetry. Since λ 6 is the highest power of λ among the quark mass matrix elements, we present as an example a possibility that the maximal CP phase π 2 is obtainable from a supersymmetric Z 12 discrete symmetry model.