Boosting the annihilation boost: Tidal effects on dark matter subhalos and consistent luminosity modeling

In the cold dark matter paradigm, structures form hierarchically, implying that large structures contain smaller substructures. These subhalos will enhance signatures of dark matter annihilation such as gamma rays. In the literature, typical estimates of this boost factor assume a concentration-mass relation for field halos, to calculate the luminosity of subhalos. However, since subhalos accreted in the gravitational potential of their host loose mass through tidal stripping and dynamical friction, they have a quite characteristic density profile, different from that of the field halos of the same mass. In this work, we quantify the effect of tidal stripping on the boost factor, by developing a semi-analytic model that combines mass-accretion history of both the host and subhalos as well as subhalo accretion rates. We find that when subhalo luminosities are treated consistently, the boost factor increases by a factor 2-5, compared to the typical calculation assuming a field-halo concentration. This holds for host halos ranging from sub-galaxy to cluster masses and is independent of the subhalo mass function or specific concentration-mass relation. The results are particularly relevant for indirect dark matter searches in the extragalactic gamma-ray sky.Comment: 9 pages, 5 figures, 1 table. Accepted for publication in PR

Strong support for the millisecond pulsar origin of the Galactic center GeV excess

Using gamma-ray data from the Fermi Large Area Telescope, various groups have identified a clear excess emission in the Inner Galaxy, at energies around a few GeV. This excess resembles remarkably well a signal from dark-matter annihilation. One of the most compelling astrophysical interpretations is that the excess is caused by the combined effect of a previously undetected population of dim gamma-ray sources. Because of their spectral similarity, the best candidates are millisecond pulsars. Here, we search for this hypothetical source population, using a novel approach based on wavelet decomposition of the gamma-ray sky and the statistics of Gaussian random fields. Using almost seven years of Fermi-LAT data, we detect a clustering of photons as predicted for the hypothetical population of millisecond pulsar, with a statistical significance of 10.0 sigma. For plausible values of the luminosity function, this population explains 100% of the observed excess emission. We argue that other extragalactic or Galactic sources, a mismodeling of Galactic diffuse emission, or the thick-disk population of pulsars are unlikely to account for this observation.Comment: 6+10 pages, 3+10 figures, 1 table; v2 updated to pass 8 Fermi data, additional supplemental material with extended discussion (conclusions unchanged); v3 matches PRL version with further checks (conclusions unchanged

Inverse-Compton Emission from Clusters of Galaxies: Predictions for ASTRO-H

The intra-cluster medium of several galaxy clusters hosts large-scale regions of diffuse synchrotron radio emission, known as radio halos and relics, which demonstrate the presence of magnetic fields and relativistic electrons in clusters. These relativistic electrons should also emit X-rays through inverse-Compton scattering off of cosmic microwave background photons. The detection of such a non-thermal X-ray component, together with the radio measurement, would permit to clearly separate the magnetic field from the relativistic electron distribution as the inverse-Compton emission is independent from the magnetic field in the cluster. However, non-thermal X-rays have not been conclusively detected from any cluster of galaxies so far. In this paper, for the first time, we model the synchrotron and inverse-Compton emission of all clusters hosting radio halos and relics for which the spectral index can be determined. We provide constraints on the volume-average magnetic field by comparing with current X-ray measurements. We then estimate the maximum volume-average magnetic field that will allow the detection of inverse-Compton hard X-rays by the ASTRO-H satellite. We found that several clusters are good targets for ASTRO-H to detect their inverse-Compton emission, in particular that corresponding to radio relics, and propose a list of promising targets for which ASTRO-H can test $\ge1$~$\mu$G magnetic fields. We conclude that future hard X-ray observations by the already-operating NuSTAR and the soon-to-be-launched ASTRO-H definitely have the potential to shed light on the long-sought non-thermal hard-X-ray emission in clusters of galaxies.Comment: 28 pages, 5 figures, 9 Tables. Accepted by A&

Reversing subdivision rules: local linear conditions and observations on inner products

AbstractIn a previous work (Samavati and Bartels, Comput. Graphics Forum 18 (1998) 97–119) we investigated how to reverse subdivision rules using global least-squares fitting. This led to multiresolution structures that could be viewed as semiorthogonal wavelet systems whose inner product was that for finite-dimensional Cartesian vector space. We produced simple and sparse reconstruction filters, but had to appeal to matrix factorization to obtain an efficient, exact decomposition. We also made some observations on how the inner product that defines the semiorthogonality influences the sparsity of the reconstruction filters. In this work we carry the investigation further by studying biorthogonal systems based upon subdivision rules and local least-squares fitting problems that reverse the subdivision. We are able to produce multiresolution structures for some common univariate subdivision rules that have both sparse reconstruction and decomposition filters. Three will be presented here – for quadratic and cubic B-spline subdivision and for the four-point interpolatory subdivision of Dyn et al. We observe that each biorthogonal system we produce can be interpreted as a semiorthogonal system with an inner product induced on the multiresolution that is quite different from that normally used. Some examples of the use of this approach on images, curves, and surfaces are given

Reconstruction of Exposure to m-Xylene from Human Biomonitoring Data Using PBPK Modelling, Bayesian Inference, and Markov Chain Monte Carlo Simulation

There are numerous biomonitoring programs, both recent and ongoing, to evaluate environmental exposure of humans to chemicals. Due to the lack of exposure and kinetic data, the correlation of biomarker levels with exposure concentrations leads to difficulty in utilizing biomonitoring data for biological guidance values. Exposure reconstruction or reverse dosimetry is the retrospective interpretation of external exposure consistent with biomonitoring data. We investigated the integration of physiologically based pharmacokinetic modelling, global sensitivity analysis, Bayesian inference, and Markov chain Monte Carlo simulation to obtain a population estimate of inhalation exposure to m-xylene. We used exhaled breath and venous blood m-xylene and urinary 3-methylhippuric acid measurements from a controlled human volunteer study in order to evaluate the ability of our computational framework to predict known inhalation exposures. We also investigated the importance of model structure and dimensionality with respect to its ability to reconstruct exposure

Implications of multi-Regge limits for the Bern-Dixon-Smirnov conjecture

Planar ${\cal N} =4$ super Yang-Mills SU(N) theory is expected to exhibit stringy behavior, anticipated by the 't Hooft genus expansion and the $AdS/CFT$ correspondence. We examine the Bern-Dixon-Smirnov (BDS) conjecture for $n$-gluon amplitudes in the context of single-Regge and multi-Regge limits and show that these amplitudes have the expected Regge form in the Euclidean region.Comment: 48 pages, 8 figures; Noted added commenting on related work which appeared after the initial posting. References and clarifications added, as well as typos correcte

Progress in drug metabolism, volume 1 Edited by J. W. Bridges and L. F. Chasseaud John Wiley and Sons; London, New York, Sydney, Toronto, 1976 xiii + 286 pages. $ 19.75, £ 9.80

Objective: People with psychotic disorders have an increased metabolic risk and a shortened life expectancy compared to the general population. Two large studies showed that metabolic disorders were untreated in a majority of the patients. Since then, guidelines have urged monitoring of metabolic health. This study examined the course of metabolic disorders over time in people with psychotic disorders and investigated current treatment rates. Methods: A total of 1,259 patients with psychotic disorders, as defined by the DSM-IV, from 4 Dutch mental health institutions participated in 3 yearly assessments of the Pharmacotherapy Monitoring and Outcome Survey (PHAMOUS) between 2006 and 2014. Patients' metabolic parameters were measured, and the use of pharmacologic treatment for hypertension (systolic blood pressure >= 140 mm Hg and/or diastolic blood pressure >= 90 mm Hg), dyslipidemia (5% = 2.5 mmol/L or SCORE risk >= 10% and LDL cholesterol level >= 1.8 mmol/L and/or triglycerides >= 2.3 mmol/L), and hyperglycemia (hemoglobin A(1c) concentration > 7% and/or fasting glucose concentration >= 7.2 mmol/L) was recorded. Results: Prevalence of the metabolic syndrome, as defined by the National Cholesterol Education Program criteria, was > 50% at each assessment. On the basis of the European Society of Cardiology guidelines, pharmacotherapy for metabolic disorders was recommended for 52%-59% of the patients at each assessment. Treatment rates with antihypertensive (from 31% to 38%, P <.001) pharmacotherapy increased throughout the assessments. However, half of the patients were not treated for their metabolic risk factors while being monitored for 3 years or longer. Older patients were more likely to receive treatment, and patients who received treatment had lower blood pressure and lower cholesterol and triglyceride concentrations than patients not receiving the recommended treatment. Conclusions: Metabolic risk factors are still seriously undertreated in people with psychotic disorders. Better adherence to and better implementation of guidelines about monitoring and treating metabolic disorders in psychiatry are crucial. (C) Copyright 2017 Physicians Postgraduate Press, Inc