2012 (IPP)

Permanent URI for this collectionhttp://localhost:4000/handle/11007/150

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Now showing 1 - 10 of 17
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    Cosmological solution of Machian gravity
    (IUCAA, 2015-02) Das, Santanu
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    On the wavy mechanics of particles
    (IUCAA, 2015-02) Das, Santanu
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    Machian gravity and the giant galactic forces
    (IUCAA, 2015-02) Das, Santanu
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    Revealing Non-circular beam effect in WMAP-7 CMB maps with BipoSH measures of Statistical Isotropy
    (IUCAA, 2015-02) Joshi, Nidhi; Das, Santanu; Mitra, Sanjit
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    WMAP anomaly : Weak lensing in disguise
    (IUCAA, 2015-02) Rotti, Aditya; Aich, Moumita; Souradeep, Tarun
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    Dipole leakage and low CMB multipoles
    (IUCAA, 2015-02) Das, Santanu; Souradeep, Tarun
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    A New Window into Stochestic Gravitational Wave Background
    (2013-09-20) Rotti, Aditya; Souradeep, Tarun
    A stochastic gravitational wave background (SGWB) would gravitationally lens the cosmic mi- crowave background (CMB) photons. We correct the results provided in existing literature for modi cations to the CMB polarization power spectra due to lensing by gravitational waves (GW). Weak lensing by gravitational waves (GW) distorts all the four CMB power spectra, however its e ect is most striking in the mixing of power between the E-mode and B-mode of CMB polarization. This suggests the possibility of using measurements of the CMB angular power spectra to constrain the energy density ( GW) of the SGWB. Using current data sets (QUAD, WMAP and ACT), we nd that the most stringent constraints on the present GW come from measurements of the angular power spectra of CMB temperature anisotropies. In near future more stringent bounds on GW can be expected with improved upper limits on the B-modes of CMB polarization. Any detection of B-modes of CMB polarization above the expected signal from large scale structure(LSS) lensing could be a signal for a SGWB
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    A Minimal Model of Neutrino Flavor
    (2012-07) Luhn, Christoph; Parattu, Krishna Mohan; Wingerter, Akin
    Models of neutrino mass which attempt to describe the observed lepton mixing pat- tern are typically based on discrete family symmetries with a non-Abelian and one or more Abelian factors. The latter so-called shaping symmetries are imposed in order to yield a realistic phenomenology by forbidding unwanted operators. Here we propose a supersymmetric model of neutrino avor which is based on the group T7 and does not require extra ZN or U(1) factors, which makes it the smallest realistic family symmetry that has been considered so far. At leading order, the model pre- dicts tribimaximal mixing which arises completely accidentally from a combination of the T7 Clebsch-Gordan coe cients and suitable avon alignments. Next-to-leading order (NLO) operators break the simple tribimaximal structure and render the model compatible with the recent results of the Daya Bay and Reno collaborations which have measured a reactor angle of around 9 . Problematic NLO deviations of the other two mixing angles can be controlled in an ultraviolet completion of the model.
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    Characterizing Foreground for redshifted 21-cm radiation: 150 MHz GMRT observations
    (2013-09-05) Ghosh, Abhik; Prasad, Jayanti; Bharadwaj, Somnath; Ali, Saiyad; Chengalur, Jayaram N.