## [1108.4421] Intermediate-mass-ratio black hole binaries II: Modeling Trajectories and Gravitational Waveforms

Authors: Hiroyuki Nakano, Yosef Zlochower, Carlos O. Lousto, Manuela Campanelli

Date: 22 Aug 2011

#### Aug 05, 2011

1108.1163 (/preprints)
2011-08-05, 13:01 

## [1108.0995] Constructing EOB dynamics with numerical energy flux for intermediate-mass-ratio inspirals

Authors: Wen-Biao Han, Zhoujian Cao

Date: 4 Aug 2011

Abstract: A new scheme for computing dynamical evolutions and gravitational radiations for intermediate-mass-ratio inspirals (IMRIs) based on an effective one-body (EOB) dynamics plus Teukolsky perturbation theory is built in this paper. In the EOB framework, the dynamics essentially affects the resulted gravitational waveform for binary compact star system. This dynamics includes two parts. One is the conservative part which comes from effective one-body reduction. The other part is the gravitational back reaction which contributes to the shrinking process of the inspiral of binary compact star system. Previous works used analytical waveform to construct this back reaction term. Since the analytical form is based on post-Newtonian expansion, the consistency of this term is always checked by numerical energy flux. Here we directly use numerical energy flux by solving the Teukolsky equation via the frequency-domain method to construct this back reaction term. And the conservative correction to the leading order terms in mass-ratio is included in the deformed-Kerr metric and the EOB Hamiltonian. We try to use this method to simulate not only quasi-circular adiabatic inspiral but also the nonadiabatic plunge phase. For several different spinning black holes, we demonstrate and compare the resulted dynamical evolutions and gravitational waveforms.

#### Aug 05, 2011

1108.0995 (/preprints)
2011-08-05, 13:00 

## [1108.0812] High signal-to-noise ratio observations and the ultimate limits of precision pulsar timing

Authors: Stefan Oslowski, Willem van Straten, George Hobbs, Matthew Bailes, Paul Demorest

Date: 3 Aug 2011

Abstract: We demonstrate that the sensitivity of high-precision pulsar timing experiments will be ultimately limited by the broadband intensity modulation that is intrinsic to the pulsar's stochastic radio signal. That is, as the peak flux of the pulsar approaches that of the system equivalent flux density, neither greater antenna gain nor increased instrumental bandwidth will improve timing precision. These conclusions proceed from an analysis of the covariance matrix used to characterise residual pulse profile fluctuations following the template matching procedure for arrival time estimation. We perform such an analysis on 25 hours of high-precision timing observations of the closest and brightest millisecond pulsar, PSR J0437-4715. In these data, the standard deviation of the post-fit arrival time residuals is approximately four times greater than that predicted by considering the system equivalent flux density, mean pulsar flux and the effective width of the pulsed emission. We develop a technique based on principal component analysis to mitigate the effects of shape variations on arrival time estimation and demonstrate its validity using a number of illustrative simulations. When applied to our observations, the method reduces arrival time residual noise by approximately 20%. We conclude that, owing primarily to the intrinsic variability of the radio emission from PSR J0437-4715 at 20 cm, timing precision in this observing band better than 30 - 40 ns in one hour is highly unlikely, regardless of future improvements in antenna gain or instrumental bandwidth. We describe the intrinsic variability of the pulsar signal as stochastic wideband impulse modulated self-noise (SWIMS) and argue that SWIMS will likely limit the timing precision of every millisecond pulsar currently observed by Pulsar Timing Array projects as larger and more sensitive antennae are built in the coming decades.

#### Aug 03, 2011

1108.0812 (/preprints)
2011-08-03, 23:42 

## [1107.3585] Model-Independent Comparisons of Pulsar Timings to Scalar-Tensor Gravity

Authors: M.W. Horbatsch, C.P. Burgess

Date: 18 Jul 2011

Abstract: Observations of pulsar timing provide strong constraints on scalar-tensor theories of gravity, but these constraints are traditionally quoted as limits on the microscopic parameters (like the Brans-Dicke coupling, for example) that govern the strength of scalar-matter couplings at the particle level in particular models. Here we present fits to timing data for several pulsars directly in terms of the phenomenological couplings (masses, scalar charges, moments of inertia and so on) of the stars involved, rather than to the more microscopic parameters of a specific model. For instance, for the double pulsar PSR J0737-3039A/B we find with 95% confidence that m_A = (1.30 +/- 0.04)m_sun, m_B = (1.21 +/- 0.04)m_sun, while the scalar-charge to mass ratios satisfy |a_A| < 0.25, |a_B| < 0.25 and |a_B - a_A| < 0.0022. These constraints are independent of the details of the scalar tensor model involved, and of assumptions about the stellar equations of state. Our fits can be used to constrain a broad class of scalar tensor theories by computing the fit quantities as functions of the microscopic parameters in any particular model, reproducing in particular standard constraints when applied to Brans-Dicke and quasi-Brans-Dicke models.

#### Aug 02, 2011

1107.3585 (/preprints)
2011-08-02, 23:28 

## [1108.0205] Galactic foreground contributions to the WMAP5 maps

Authors: N. Macellari (1), E. Pierpaoli (1), C. Dickinson (2), J. Vaillancourt (3) ((1) USC, (2) JBCA, University of Manchester, (3) Caltech)

Date: 31 Jul 2011

Abstract: We compute the cross correlation of the intensity and polarisation from the 5-year WMAP data in different sky-regions with respect to template maps for synchrotron, dust, and free-free emission. We derive the frequency dependence and polarisation fraction for all three components in 48 different sky regions of HEALPix (Nside=2) pixelisation. The anomalous emission associated with dust is clearly detected in intensity over the entire sky at the K (23 GHz) and Ka (33 GHz) WMAP bands, and is found to be the dominant foreground at low Galactic latitude, between b=-40 and b=+10. The synchrotron spectral index obtained from the K and Ka WMAP bands from an all-sky analysis is -3.32\pm 0.12 for intensity and -3.01\pm0.03 for the polarised intensity. The polarisation fraction of the synchrotron is constant in frequency and increases with latitude from ~5% near the Galactic plane up to ~40% in some regions at high latitude; the average value for |b|<20 is 8.6\pm1.7 (stat) \pm0.5 (sys) % while for |b|>20 it is 19.3\pm0.8 (stat) \pm 0.5 (sys) %. Anomalous dust and free-free emission appear to be relatively unpolarised…[Abridged]…the average polarisation fraction of dust-correlated emission at K-band is 3.2\pm0.9 (stat) \pm 1.5 (sys) %, or less than 5% at 95% confidence. When comparing real data with simulations, 8 regions show a detected polarisation above the 99th percentile of the distribution from simulations with no input foreground polarisation, 6 of which are detected at above 2sigma and display polarisation fractions between 2.6% and 7.2%, except for one anomalous region, which has 32\pm12%. The dust polarisation values are consistent with the expectation from spinning-dust emission, but polarised dust emission from magnetic-dipole radiation cannot be ruled out. Free-free emission was found to be unpolarised with an upper limit of 3.4% at 95% confidence.

#### Aug 02, 2011

1108.0205 (/preprints)
2011-08-02, 07:41 

## [1108.0302] What the information paradox is {\it not}

Authors: Samir D. Mathur

Date: 1 Aug 2011

Abstract: There still exist many confusions about the black hole information paradox and its resolution. We first give a precise formulation of the paradox, in four steps A-D. Then we examine several proposals for resolving the paradox. We note that in each case one of these four steps has been ignored, so that the proposal does not really target the essence of the paradox. Finally, we give a brief summary of the fuzzball construction and argue that it resolves the paradox in string theory. This resolution contains a deep lesson -- the phase space of quantum gravity is so large that the measure in the path integral can compete with the classical action for macroscopic objects undergoing gravitational collapse.

#### Aug 02, 2011

1108.0302 (/preprints)
2011-08-02, 07:41 

## [1107.5809] Second-generation microlensing planet surveys: a realistic simulation

Authors: Yossi Shvartzvald, Dan Maoz

Date: 28 Jul 2011

Abstract: Microlensing surveys, which have discovered about a dozen extrasolar planets to date, have focused on the small minority of high-magnification lensing events, which have a high sensitivity to planet detection. In contrast, second-generation experiments, of the type that has recently begun, monitor continuously also the majority of low-magnification events. We carry out a realistic numerical simulation of such experiments. We simulate scaled, solar-like, eight-planet systems, studying a variety of physical parameters (planet frequency, scaling of the snowline with stellar mass R_snow ~ Mˆs), and folding in the various observational parameters (cadence, experiment duration), with sampling sequences and photometric error distributions taken from the real ongoing experiment. We quantify the dependence of detected planet yield on cadence and experiment duration, e.g., the yield is doubled when going from 3-hour to 15-minute baseline cadences, or from an 80-day-long to a 150-day-long experiment. There is a degeneracy between the snowline scaling index s and the abundance of planetary systems that can be inferred from the experiment. After 4 years, the ongoing second-generation experiment will discover of the order of 50 planets, and thus will be able to determine the frequency of snowline planet occurrence to 10-30% accuracy, assuming the fraction of stars hosting such planets is between 1/3 and 1/10, and a snowline index in the range s=0.5 to 2. If most planetary systems are solar analogs, over 65% of the detected planets will be "Jupiters", five in six of the detected anomalies will be due to a single planet, and one in six will reveal two planets in a single lensing event.

#### Aug 01, 2011

1107.5809 (/preprints)
2011-08-01, 06:42