1106.5507
Galaxy bias and non-linear structure formation in general relativity
Baldauf, Seljak, Senatore, Zaldarriaga
* 48 pages! 4 figures.
Non-Gaussianity in the initial conditions can show up as scale dependent bias at the largest scales--must include GR effects. Provide GR generalization of the bias, valid for both Gaussian and non-Gaussian initial conditions. Small-scale collapse in the Fermi frame (locally almost flat), while long-wavelength modes are in the quasi linear regime, and are encoded in the mapping from the cosmological frame to the local frame. The long-wavelength modes in linear bias, the dynamics is encoded in the local curvature of the universe---allows for GR generalization of bias in Newtonian settings. Bias due to non-Gaussianties doesn't need to vanish at Hubble scales or larger. For non-G of the local kind, the bias goes to a constant. Application: not necessary to perform large N-body sims to extract information on long-wavelength modes: Simply add long-wavelength modes by adding curvature to the simulation and rescaling the coordinates.
* General-relativistic generalization of the galaxy bias (eech).
1106.5508
ELMAG: a Monte Carlo simulation of EM cascades on the extragalactic BG light and in magnetic fields
Kachelriess, Ostapchenko, Tomas
Extragalactic background light (EBL) interacting with high-energy photon/electron cascades, simulated by MC. Pair production, inverse Compton scattering, synchrotron losses, deflections of charged component in extragalactic magnetic field (EGMF) included. Weighted sampling employed. Simulation provides the energy, observation angle, and the time delay of secondary cascade particles. Possible applications: TeV blazars and influence of EGMF on their spectra; calculating contribution from UHCR to dark matter to diffuse extragalactic gamma-ray BG. Derives limits on the EGMF.
1106.5646
Pulse profile stability of the Crab pulsar
Jain, Paul
Use RXTE archival data over the last decade, in soft (2-20keV) and hard (30-100keV) X-ray, to study the stability of the Crab pulsar pulse profile. Check separation, intensity and widths of two peaks. No significant time dependency found in the pulse shape; stable for the past 10 years. Some description of the two peak types.
* what was that about?
1106.5508
ELMAG: a Monte Carlo simulation of EM cascades on the extragalactic BG light and in magnetic fields
Kachelriess, Ostapchenko, Tomas
Extragalactic background light (EBL) interacting with high-energy photon/electron cascades, simulated by MC. Pair production, inverse Compton scattering, synchrotron losses, deflections of charged component in extragalactic magnetic field (EGMF) included. Weighted sampling employed. Simulation provides the energy, observation angle, and the time delay of secondary cascade particles. Possible applications: TeV blazars and influence of EGMF on their spectra; calculating contribution from UHCR to dark matter to diffuse extragalactic gamma-ray BG. Derives limits on the EGMF.
1106.5646
Pulse profile stability of the Crab pulsar
Jain, Paul
Use RXTE archival data over the last decade, in soft (2-20keV) and hard (30-100keV) X-ray, to study the stability of the Crab pulsar pulse profile. Check separation, intensity and widths of two peaks. No significant time dependency found in the pulse shape; stable for the past 10 years. Some description of the two peak types.
* what was that about?
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