Download or read book Adiabatic Dark Matter Density Cusps Around Supermassive Black Holes and Dark Matter Detection written by Augusto Medeiros Da Rosa and published by . This book was released on 2019 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: The growth of a black hole surrounded by dark matter can lead to a significant enhancement of the dark matter density close to the hole. We investigate this effect, focusing on the phenomenologically interesting case where the black hole is supermassive and is embedded in a galactic dark matter halo, although the formalism developed does not depend on that fact. Due to the enhanced gravitational potential, the dark matter will tend to cluster around the black hole. The precise details of this clustering will, in general, depend on the formation process of the black hole. However, if the black hole grows slowly with respect to the orbital timescales of the local galactic potential, the density cusp only depends on the black hole’s mass and spin, as well as on the local distribution of orbits. The density cusp generated by the growing black hole is called an adiabatic spike. In the context of dark matter density cusps, these spikes were first investigated by Gondolo and Silk (1999), using a phase space analysis. General relativistic effects originating from the black hole’s mass were calculated by Sadeghian, Ferrer, and Will (2013), revealing an enhancement of the density in the spike. Our work extends this calculation to include the effects of spin. We find a further enhancement to the spike that is strongly dependent on the black hole’s spin parameter, meaning that it cannot be ignored for rapidly spinning black holes. We estimate its impact in local annihilation rates for two particular physical processes: particle dark matter annihilation in the s-channel, and the merger rate of binaries composed of primordial black holes in the local universe. We also present a derivation of the two-body collision rate per four-volume in terms of the phase space distribution that can be used in any coordinate system.
Download or read book Supermassive Black Holes in the Distant Universe written by A.J. Barger and published by Springer Science & Business Media. This book was released on 2013-11-09 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quasars, and the menagerie of other galaxies with "unusual nuclei", now collectively known as Active Galactic Nuclei or AGN, have, in one form or another, sparked the interest of astronomers for over 60 years. The only known mechanism that can explain the staggering amounts of energy emitted by the innermost regions of these systems is gravitational energy release by matter falling towards a supermassive black hole --- a black hole whose mass is millions to billions of times the mass of our Sun. AGN emit radiation at all wavelengths. X-rays originating at a distance of a few times the event horizon of the black hole are the emissions closest to the black hole that we can detect; thus, X-rays directly reveal the presence of active supermassive black holes. Oftentimes, however, the supermassive black holes that lie at the centers of AGN are cocooned in gas and dust that absorb the emitted low energy X-rays and the optical and ultraviolet light, hiding the black hole from view at these wavelengths. Until recently, this low-energy absorption presented a major obstacle in observational efforts to map the accretion history of the universe. In 1999 and 2000, the launches of the Chandra and XMM-Newton X-ray Observatories finally broke the impasse. The impact of these observatories on X-ray astronomy is similar to the impact that the Hubble Space Telescope had on optical astronomy. The astounding new data from these observatories have enabled astronomers to make enormous advances in their understanding of when accretion occurs.
Download or read book Illuminating Dark Matter written by Rouven Essig and published by Springer Nature. This book was released on 2019-11-22 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on a Simons Symposium held in 2018, the proceedings in this volume focus on the theoretical, numerical, and observational quest for dark matter in the universe. Present ground-based and satellite searches have so far severely constrained the long-proposed theoretical models for dark matter. Nevertheless, there is continuously growing astrophysical and cosmological evidence for its existence. To address present and future developments in the field, novel ideas, theories, and approaches are called for. The symposium gathered together a new generation of experts pursuing innovative, more complex theories of dark matter than previously considered.This is being done hand in hand with experts in numerical astrophysical simulations and observational techniques—all paramount for deciphering the nature of dark matter. The proceedings volume provides coverage of the most advanced stage of understanding dark matter in various new frameworks. The collection will be useful for graduate students, postdocs, and investigators interested in cutting-edge research on one of the biggest mysteries of our universe.
Download or read book Phenomenology of Dark Matter Particles at the Centers of Galaxies written by Thomas Lacroix and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unveiling the nature of dark matter is one of the greatest challenges of modern physics, at the interface between astrophysics, cosmology and particle physics. In this thesis, I tackle various aspects of indirect searches for dark matter particles, which provide a complementary approach to direct detection or collider experiments. We are now entering into an era of instruments with outstanding capabilities, so it was timely to tackle the problem of the dark matter density profile at the centers of galaxies with novel methods, which motivated this thesis. Taking advantage of these technological advances, I investigate new ways of probing the very central part of dark matter halos, especially focusing on dark matter spikes, i.e. very strong enhancements of the dark matter density that can form around supermassive black holes. I show that we can go beyond standard dark matter searches by studying photon emission from electrons and positrons produced in dark matter annihilation processes. In this context, I describe a new cosmic-ray propagation technique to account for injection by spiky distributions at the centers of galaxies. I develop novel models of the diffuse emission in the central regions of galaxies, focusing not only on the center of the Milky Way, but on the central regions of other galaxies as well. This allows me to explain recently reported observations and make predictions for future observations.
Download or read book Dark Matter in the Universe written by John N. Bahcall and published by World Scientific. This book was released on 2004 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: If standard gravitational theory is correct, then most of the matterin the universe is in an unidentified form which does not emit enoughlight to have been detected by current instrumentation. This book isthe second editon of the lectures given at the 4th Jerusalem WinterSchool for Theoretical Physics, with new material added. The lecturesare devoted to the missing matter problem in the universe, thesearch to understand dark matter. The goal of this volume is to makecurrent research work on unseen matter accessible to students withoutprior experience in this area and to provide insights for experts inrelated research fields. Due to the pedagogical nature of the originallectures and the intense discussions between the lecturers and thestudents, the written lectures included in this volume often containtechniques and explanations not found in more formal journalpublications.
Download or read book Dark Sky Dark Matter written by J.M Overduin and published by CRC Press. This book was released on 2002-09-01 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Olbers' paradox states that given the Universe is unbounded, governed by the standard laws of physics, and populated by light sources, the night sky should be ablaze with light. Obviously this is not so. However, the paradox does not lie in nature but in our understanding of physics. A Universe with a finite age, such as follows from big-bang theor
Download or read book Dark Matter in Astro and Particle Physics written by Hans Volker Klapdor-Kleingrothaus and published by Springer Science & Business Media. This book was released on 2001 with total page 770 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dark matter has become one of the most exciting and central fields of astrophysics, particle physics and cosmology. The lectures and talks in these proceedings emphasize equally the experimental and theoretical perspectives of the ongoing search for dark matter in the universe, stressing in particular the interplay between astro- and particle physics.
Download or read book Dark Matter in the Universe written by Marc S. Seigar and published by Morgan & Claypool Publishers. This book was released on 2015-10-12 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of dark matter, in both astrophysics and particle physics, has emerged as one of the most active and exciting topics of research in recent years. This book reviews the history behind the discovery of missing mass (or unseen mass) in the Universe, and ties this into the proposed extensions to the Standard Model of Particle Physics (such as Supersymmetry), which were being proposed within the same time frame. This book is written as an introduction to these problems at the forefront of astrophysics and particle physics, with the goal of conveying the physics of dark matter to beginning undergraduate majors in scientific fields. The book goes onto describe existing and upcoming experiments and techniques, which will be used to detect dark matter either directly on indirectly.
Download or read book From Supermassive Black Holes to Supersymmetric Dark Matter written by Savvas Michael Koushiappas and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: It is without doubt that in recent years cosmology has entered an era where cosmological parameters are now measured precisely enough to derive conclusions about the underlying characteristics of the Universe. I present an overview of the methods used to estimate the parameters that lead to the standard cosmological model. After a brief detour on the current understanding of the mechanisms that lead to galaxy formation, I present a model in which the seeds of supermassive black holes observed in galactic spheroids form out of the lowest angular momentum gas in proto-galaxies at high redshift. I assume that the gas in early-forming, rare-peak halos has a distribution of specific angular momentum similar to that derived for the dark matter. In halos more massive than a critical threshold, proto-galactic disks are gravitationally unstable and experience an efficient viscosity that transfers angular momentum outward allowing mass inflow. This process continues until the first massive stars disrupt the disk. The seed black holes created in this manner have a characteristic mass scale, roughly independent of the redshift of formation. By the redshift of reionization, the comoving mass density is comparable to that inferred from observations, with room for appropriate additional luminous growth during a later quasar accretion phase. The hierarchical merger process naturally leads to a linear correlation between black-hole mass and stellar spheroid mass. Quite orthogonal to this study, I estimate the probability of detecting gamma-rays from the annihilation of neutralino dark matter in the Milky Way substructure. I characterize substructure statistically based on Monte Carlo realizations of the formation of a Milky Way-like halo. I find that it may be possible for upcoming experiments to detect gamma-rays from dark matter substructure if the neutralino is relatively light, while for a heavy neutralino such a detection would be unlikely. I find that the probability of detection is sensitive to poorly-constrained input parameters, particularly those that characterize the primordial power spectrum. I conclude that the lack of a detected gamma-ray signal gives very little information about the supersymmetric parameter space due to uncertainties associated with both the properties of substructure and cosmological parameters.
Download or read book Progress in Dark Matter Research written by J. Val Blain and published by Nova Publishers. This book was released on 2005 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is generally believed that most of the matter in the universe is dark, i.e. cannot be detected from the light which it emits (or fails to emit). Its presence is inferred indirectly from the motions of astronomical objects, specifically stellar, galactic, and galaxy cluster/supercluster observations. It is also required in order to enable gravity to amplify the small fluctuations in the cosmic microwave background enough to form the large-scale structures that we see in the universe today. For each of the stellar, galactic, and galaxy cluster/supercluster observations the basic principle is that if we measure velocities in some region, then there has to be enough mass there for gravity to stop all the objects flying apart. Dark matter has important consequences for the evolution of the Universe and the structure within it. According to general relativity, the Universe must conform to one of three possible types: open, flat, or closed. The total amount of mass and energy in the universe determines which of the three possibilities applies to the Universe. In the case of an open Universe, the total mass and energy density (denoted by the Greek letter Omega) is less than unity. If the Universe is closed, Omega is greater than unity. For the case where Omega is exactly equal to one the Universe is "flat". This book details leading-edge research from around the globe.
Download or read book Dark Matter In Astroparticle And Particle Physics Proceedings Of The 6th International Heidelberg Conference written by Hans Volker Klapdor-kleingrothaus and published by World Scientific. This book was released on 2008-05-09 with total page 654 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dark matter remains one of the central mysteries in modern physics, although modern astronomical observations and particle physics experiments are providing vital clues in uncovering its true nature. The Dark2007 Conference brought together world-leading researchers in both astrophysics and particle physics, providing them with an opportunity to present their latest results and engage in discussion on their meaning and future direction. This book is important in its field, as it provides a vital snapshot of the seemingly disparate areas of dark matter research and provides an overview of current ideas and future directions.
Download or read book Dark Matter and Dark Energy written by Sabino Matarrese and published by Springer Science & Business Media. This book was released on 2011-02-10 with total page 413 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book brings together reviews from leading international authorities on the developments in the study of dark matter and dark energy, as seen from both their cosmological and particle physics side. Studying the physical and astrophysical properties of the dark components of our Universe is a crucial step towards the ultimate goal of unveiling their nature. The work developed from a doctoral school sponsored by the Italian Society of General Relativity and Gravitation. The book starts with a concise introduction to the standard cosmological model, as well as with a presentation of the theory of linear perturbations around a homogeneous and isotropic background. It covers the particle physics and cosmological aspects of dark matter and (dynamical) dark energy, including a discussion of how modified theories of gravity could provide a possible candidate for dark energy. A detailed presentation is also given of the possible ways of testing the theory in terms of cosmic microwave background, galaxy redshift surveys and weak gravitational lensing observations. Included is a chapter reviewing extensively the direct and indirect methods of detection of the hypothetical dark matter particles. Also included is a self-contained introduction to the techniques and most important results of numerical (e.g. N-body) simulations in cosmology. " This volume will be useful to researchers, PhD and graduate students in Astrophysics, Cosmology Physics and Mathematics, who are interested in cosmology, dark matter and dark energy.
Download or read book Dark Matter in Astro and Particle Physics written by Hans-Volker Klapdor-Kleingrothaus and published by Springer Science & Business Media. This book was released on 2006-02-23 with total page 678 pages. Available in PDF, EPUB and Kindle. Book excerpt: TheFifthHEIDELBERGInternationalConferenceonDarkMatterinAst- and Particle Physics, DARK 2004, took place at Texas A&M University, College Station Texas, USA, October 3–9, 2004. It was, after Cape Town 2002, the second conference of this series held outside Germany. The earlier meetings, starting in 1996, were held in Heidelberg. Dark Matter is still one of the most exciting and central ?elds of ast- physics, particle physics and cosmology. The conference covered, as usual for this series, a large range of topics, theoretical and experimental. Theoretical talks covered SUSY/SUGRA phenomenology, which provides at present a preferred theoretical framework for the existence of cold dark matter. Also included were other possible explanations of dark matter such as SUSY Q balls, exciting New Symmetries, etc. The most important experiments in the underground search for cold and hot dark matter were presented. Talks describing the current experimental dark matter bounds, what might be obtained in the near future, and the reach of future large (i.e. one ton) detectors were given. The potential of future colliders to correlate accelerator physics with dark matter searches was also outlined. Thus the reader will be able to see the present status and future prospects in the search for dark matter. The exciting astronomical evidence for dark matter and corresponding observations concerning the Milky Way’s black hole, high-redshift clusters, wakes in dark matter halos were other important topics at the conference.
Download or read book Identification Of Dark Matter The Proceedings Of The Sixth International Workshop written by Minos Axenides and published by World Scientific. This book was released on 2007-08-31 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is the latest in a prominent biannual series of scientific meetings on the exciting research topics of dark matter and, more recently, of dark energy. It contains a state-of-the-art update on detection efforts by experimental groups around the world trying to pin down exotic new forms of matter under the names of axions, neutralinos, wimps, primordial black holes, q balls, sterile neutrinos, as well as a tantalizing new form of dark energy component called phantom energy and quintessence. The book is self-contained as it also includes general reviews on recent cosmological observations — supernovae measurements, cosmic matter distribution surveys and cosmic radiation anisotropies — introducing even the uninitiated reader to this fascinating frontier of research.
Download or read book Sources and Detection of Dark Matter and Dark Energy in the Universe written by David B. Cline and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 551 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dark matter research is one of the most fascinating and active fields among current high-profile scientific endeavours. It holds the key to all major breakthroughs to come in the fields of cosmology and astroparticle physics. The present volume is particularly concerned with the sources and the detection of dark matter and dark energy in the universe and will prove to be an invaluable research tool for all scientists who work in this field.
Download or read book Identification Of Dark Matter The Proceedings Of The Third International Workshop written by Vitaly Kudryavtsev and published by World Scientific. This book was released on 2001-05-22 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of the workshop series “The Identification of Dark Matter” is to assess critically the status of work attempting to identify what constitutes dark matter; in particular, to consider what techniques are currently being used, how successful they are, and what new techniques are likely to improve the prospects for identifying dark matter candidates in the future. This proceedings volume includes reviews on major particle astrophysics topics in the field of dark matter, as well as short contributed papers.
Download or read book Matter Dark Matter and Anti Matter written by Alain Mazure and published by Springer Science & Business Media. This book was released on 2011-11-16 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: For over ten years, the dark side of the universe has been headline news. Detailed studies of the rotation of spiral galaxies, and 'mirages' created by clusters of galaxies bending the light from very remote objects, have convinced astronomers of the presence of large quantities of dark (unseen) matter in the cosmos. The most striking fact is that they seem to compromise about 95% of the matter/energy content of the universe. As for ordinary matter, although we are immersed in a sea of dark particles, including primordial neutrinos and photons from fossil cosmological radiation, both we and our environment are made of ordinary, 'baryonic' matter. Authors Mazure and Le Brun present the inventory of matter, baryonic and exotic, and investigating the nature and fate of matter's twin, anti-matter. They show how technological progress has been a result of basic research, in tandem with the evolution of new ideas, and how the combined effect of these advances might help lift the cosmic veil.
