CMB power spectrum estimation using noncircular beams

The measurements of the angular power spectrum of the Cosmic Microwave Background (CMB) anisotropy has proved crucial to the emergence of cosmology as a precision science in recent years. In this remarkable data rich period, the limitations to precision now arise from the the inability to account for finer systematic effects in data analysis. The non-circularity of the experimental beam has become progressively important as CMB experiments strive to attain higher angular resolution and sensitivity. We present an analytic framework for studying the leading order effects of a non-circular beam on the CMB power spectrum estimation. We consider a non-circular beam of fixed shape but variable orientation. We compute the bias in the pseudo-$C_l$ power spectrum estimator and then construct an unbiased estimator using the bias matrix. The covariance matrix of the unbiased estimator is computed for smooth, non-circular beams. Quantitative results are shown for CMB maps made by a \emph{hypothetical} experiment with a non-circular beam comparable to our fits to the WMAP beam maps described in the appendix and uses a \emph{toy} scan strategy. We find that significant effects on CMB power spectrum can arise due to non-circular beam on multipoles comparable to, and beyond, the inverse average beam-width where the pseudo-$C_l$ approach may be the method of choice due to computational limitations of analyzing the large datasets from current and near future CMB experiments.Comment: 23 pages, 12 eps figures, uses RevTeX 4. Matches version accepted to Phys. Rev. D. Corrected minor typographical error in the final expression [eqn (3.23)] (post publication

Marketing of High Technology Products and Innovations -3/E

DR. JAKKI MOHR is the Ron and Judy Paige Faculty Fellow and an Associate Professor of Marketing at the University of Montana-Missoula. Prior to joining the University of Montana in the fall of 1997, Dr. Mohr was an assistant professor at the University of Colorado, Boulder (1989-1997), where she earned both the Frascona Teaching Excellence Award (1992) and the Susan Wright Research Award (1995). Before beginning her academic career, she worked in Silicon Valley in the advertising area for both Hewlett Packard\u27s Personal Computer Group and TeleVideo Systems. She received her B.B.A. from Boise State University (1982), her M.S. in Marketing from Colorado State University (1984), and her Ph.D. in Marketing from the University of Wisconsin-Madison (1989). Dr. Mohr\u27s research has been published in numerous academic and industry publication

NEUROPROTECTIVE EFFECTS OF AQUEOUS EXTRACT OF HYDROCOTYLE JAVANICA IN AMELIORATING NEUROBEHAVIORAL ALTERATION INDUCED BY MERCURY

Objective: This study aims to assess the effects of the aqueous extract of Hydrocotyle javanica (HJ) in ameliorating mercury-induced neurobehavioral toxicity.Methods: For the study, 36 adult male Swiss albino mice of 25–30 g in weight were taken. They were equally divided into six groups. Group I was treated with distilled water, Group II was treated with mercuric chloride (1.5 mg/kg), Group III was treated with HJ extract low dose (100 mg/kg), Group IV was treated with HJ extract high dose (200 mg/kg), Group V was treated with mercuric chloride plus HJ extract low dose, and Group VI was treated with mercuric chloride plus TB extract high dose. In all the groups, the doses were administered orally through oral gavage tube and the treatment lasted for 14 days. The behavioral effects evaluated were locomotor activity in the open field test, immobility in forced swimming test and anxiety in elevated plus maze test, spatial learning ability, and memory in the Morris water maze test.Results: The present study showed that mercury exposure significantly decreased the locomotor activity (p<0.001), number of annulus crossovers (p<0.001), number of open arm entries (p<0.01), time spent in open arms (p<0.001), and increased escape latency (p<0.01), path length (p<0.001), and immobility (p<0.001) in mice. The aqueous extract of HJ significantly alleviated the neurotoxic effects of mercury. The aqueous extract of HJ showed to increase the locomotor activity (p<0.01), number of annulus crossovers (p<0.001), number of open arm entries (p<0.05), and time spent in open arms (p<0.05), which was decreased in mercury-exposed mice. The HJ extract also showed to decrease the immobility (p<0.001), escape latency (p<0.05), and path length (p<0.001) in mercury-exposed mice.Conclusion: The result of the study shows that neurobehavioral changes induced by mercuric chloride were significantly reversed by the aqueous extract of HJ. Thus, base on the present study, it is concluded that HJ is effective in ameliorating the neurobehavioral deficits induced by mercury

MERCURY-INDUCED NEUROBEHAVIORAL DEFICIT AND ITS AMELIORATING EFFECTS OF AQUEOUS EXTRACT OF TRAPA BISPINOSA

Objective: The aim of this study was to evaluate the effects of aqueous extract of dry fruits of Trapa bispinosa (TB) in alleviating mercury (Hg)-induced neurobehavioral toxicity.Methods: A total of 36 adult male Swiss albino mice weighing 25–30 g were equally divided into six groups, namely I–VI. Group I received distilled water, Group II received mercuric chloride (1.5 mg/kg), Group III received TB extract low dose (150 mg/kg), Group IV received TB extract high dose (300 mg/kg), Group V received mercuric chloride plus TB extract low dose, and Group VI received mercuric chloride plus TB extract high dose. All the groups received doses orally through oral gavage tube and the treatment lasted for 14 days. The behavioral effects were evaluated with locomotor activity in the open field test (OFT), spatial learning ability and memory in the Morris water maze test (MWM), immobility in Forced swimming test (FST) and anxiety in Elevated plus maze test (EPM).Result: In the present study, it was observed that Hg-exposed mice significantly decreased the locomotor activity (p<0.001), time spent in open arms (p<0.001), number of open arm entries (p<0.01), number of annulus crossovers (p<0.001) and increased immobility (p<0.001), escape latency (p<0.01), and path length (p<0.001) in mice. The aqueous extract of TB significantly reduced the neurotoxic effects of Hg. The aqueous extract of TB showed to increase the locomotor activity (p<0.01), time spent in open arms (p<0.01), number of open arm entries (p<0.05), and number of annulus crossovers (p<0.001), which was decreased in Hg-exposed mice. TB extract also showed to decrease the immobility (p<0.001), escape latency (p<0.05), and path length (p<0.001) in Hg-fed mice.Conclusion: On the basis of the results obtained from the behavioral study, the present study indicates that mercuric chloride caused neurobehavioral changes which were significantly reversed by the aqueous extract of TB. Thus, TB was found to be effective in ameliorating the neurobehavioral deficit induced by Hg exposure

Non-Circular beam correction to the CMB power spectrum

In the era of high precision CMB measurements, systematic effects are beginning to limit the ability to extract subtler cosmological information. The non-circularity of the experimental beam has become progressively important as CMB experiments strive to attain higher angular resolution and sensitivity. The effect of non-circular beam on the power spectrum is important at multipoles larger than the beam-width. For recent experiments with high angular resolution, optimal methods of power spectrum estimation are computationally prohibitive and sub-optimal approaches, such as the Pseudo-Cl method, are used. We provide an analytic framework for correcting the power spectrum for the effect of beam non-circularity and non-uniform sky coverage (including incomplete/masked sky maps). The approach is perturbative in the distortion of the beam from non-circularity allowing for rapid computations when the beam is mildly non-circular. When non-circular beam effect is important, we advocate that it is computationally advantageous to employ `soft' azimuthally apodized masks whose spherical harmonic transform die down fast with m.Comment: 12 pages, 2 figures; Proceedings of the Fundamental Physics With CMB workshop, UC Irvine, March 23-25, 2006, to be published in New Astronomy Review

CMB power spectrum estimation with non-circular beam and incomplete sky coverage

Over the last decade, measurements of the CMB anisotropy has spearheaded the remarkable transition of cosmology into a precision science. However, addressing the systematic effects in the increasingly sensitive, high resolution, `full' sky measurements from different CMB experiments pose a stiff challenge. The analysis techniques must not only be computationally fast to contend with the huge size of the data, but, the higher sensitivity also limits the simplifying assumptions which can then be invoked to achieve the desired speed without compromising the final precision goals. While maximum likelihood is desirable, the enormous computational cost makes the suboptimal method of power spectrum estimation using Pseudo-C_l unavoidable for high resolution data. We provide a (semi)analytic framework to estimate bias in the power spectrum due to the effect of beam non-circularity and non-uniform sky coverage including incomplete/masked sky maps and scan strategy. The approach is perturbative in the distortion of the beam from non-circularity, allowing for rapid computations when the beam is mildly non-circular. We advocate that it is computationally advantageous to employ `soft' azimuthally apodized masks whose spherical harmonic transform die down fast with m. We numerically implement our method for non-rotating beams. We present preliminary estimates of the computational cost to evaluate the bias for the upcoming CMB anisotropy probes l_max~3000, with angular resolution comparable to the Planck surveyor mission. We further show that this implementation and estimate is applicable for rotating beams on equal declination scans and possibly can be extended to simple approximations to other scan strategies.Comment: 22 pages, 7 figures. Revised presentation to highlight significance of extended results. Matches version accepted to the MNRA

Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

Ultralight vector dark matter search using data from the KAGRA O3GK run

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM