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The Effects Of Dark Matter Annihilation On Cosmic Reionization
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Book Synopsis The Effects of Dark Matter Annihilation on Cosmic Reionization by :
Download or read book The Effects of Dark Matter Annihilation on Cosmic Reionization written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We revisit the possibility of constraining the properties of dark matter (DM) by studying the epoch of cosmic reionization. Previous studies have shown that DM annihilation was unlikely to have provided a large fraction of the photons that ionized the universe, but instead played a subdominant role relative to stars and quasars. The DM, however, begins to efficiently annihilate with the formation of primordial microhalos at $z\sim100-200$, much earlier than the formation of the first stars. Therefore, if DM annihilation ionized the universe at even the percent level over the interval $z \sim 20-100$, it can leave a significant imprint on the global optical depth, $\tau$. Moreover, we show that cosmic microwave background (CMB) polarization data and future 21 cm measurements will enable us to more directly probe the DM contribution to the optical depth. In order to compute the annihilation rate throughout the epoch of reionization, we adopt the latest results from structure formation studies and explore the impact of various free parameters on our results. We show that future measurements could make it possible to place constraints on the dark matter's annihilation cross section that are at a level comparable to those obtained from the observations of dwarf galaxies, cosmic ray measurements, and studies of recombination.
Book Synopsis On Direct and Indirect Searches for Dark Matter by : Alexander Belikov
Download or read book On Direct and Indirect Searches for Dark Matter written by Alexander Belikov and published by . This book was released on 2011 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: We also study the effect of dark matter annihilation during the epoch of reionization. Although empirical evidence indicates that the universe's gas had become ionized by redshift z & ap; 6, the astrophysical models of sources of reionization remain poorly constrained. We explore the possibility that dark matter annihilations may have played a significant role in this process. Energetic electrons produced in these annihilations can scatter with the cosmic microwave background to generate relatively low energy gamma rays, which ionize and heat gas far more efficiently than higher energy prompt photons.
Book Synopsis Dark Matter Energy Deposition and Production from the Table-top to the Cosmos by : Hongwan Liu (Ph. D.)
Download or read book Dark Matter Energy Deposition and Production from the Table-top to the Cosmos written by Hongwan Liu (Ph. D.) and published by . This book was released on 2019 with total page 389 pages. Available in PDF, EPUB and Kindle. Book excerpt: The discovery of nongravitational interactions between dark matter and the Standard Model would be an important step in unraveling the nature of dark matter. If such an interaction exists, it would have profound implications on how dark matter is produced in both the early universe and in collider experiments. In addition, it would also allow dark matter to deposit energy into Standard Model particles in unexpected ways. This thesis details some recent progress made in understanding these implications, including (i) a new freezeout mechanism for thermal dark matter dominated by a 3-to-2 process within a vector portal dark sector model; (ii) a study of how the existence of dark sector bound states can influence collider, direct and indirect searches for dark matter; (iii) a new axion dark matter interferometric search using a cavity that is sensitive to the axion-induced rotation of linearly polarized light; (iv) a definitive assessment of the potential contribution of dark matter annihilation and decay to cosmic reionization; (v) new constraints on dark matter annihilation rates and decay lifetimes from 21-cm cosmology, and (vi) a new numerical code, DarkHistory, which significantly improves the computation of the ionization and thermal histories of the universe in the presence of exotic sources of energy injection. These novel ideas span length scales ranging from table-top experiments to the entire cosmos, and represent just a few of the myriad of ways in which dark matter may yet surprise us.
Book Synopsis Dark Matter and Dark Energy by : Sabino Matarrese
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.
Book Synopsis Progress in Dark Matter Research by : J. Val Blain
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.
Book Synopsis Probing Cosmic Dark Matter and Dark Energy with Weak Gravitational Lensing Statistics by : Masato Shirasaki
Download or read book Probing Cosmic Dark Matter and Dark Energy with Weak Gravitational Lensing Statistics written by Masato Shirasaki and published by Springer. This book was released on 2015-11-18 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book the applicability and the utility of two statistical approaches for understanding dark energy and dark matter with gravitational lensing measurement are introduced. For cosmological constraints on the nature of dark energy, morphological statistics called Minkowski functionals (MFs) to extract the non-Gaussian information of gravitational lensing are studied. Measuring lensing MFs from the Canada–France–Hawaii Telescope Lensing survey (CFHTLenS), the author clearly shows that MFs can be powerful statistics beyond the conventional approach with the two-point correlation function. Combined with the two-point correlation function, MFs can constrain the equation of state of dark energy with a precision level of approximately 3–4 % in upcoming surveys with sky coverage of 20,000 square degrees. On the topic of dark matter, the author studied the cross-correlation of gravitational lensing and the extragalactic gamma-ray background (EGB). Dark matter annihilation is among the potential contributors to the EGB. The cross-correlation is a powerful probe of signatures of dark matter annihilation, because both cosmic shear and gamma-ray emission originate directly from the same dark matter distribution in the universe. The first measurement of the cross-correlation using a real data set obtained from CFHTLenS and the Fermi Large Area Telescope was performed. Comparing the result with theoretical predictions, an independent constraint was placed on dark matter annihilation. Future lensing surveys will be useful to constrain on the canonical value of annihilation cross section for a wide range of mass of dark matter annihilation. Future lensing surveys will be useful to constrain on the canonical value of annihilation cross section for a wide range of mass of dark matter.
Book Synopsis Matter, Dark Matter, and Anti-Matter by : Alain Mazure
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.
Book Synopsis Cosmological Inflation, Dark Matter and Dark Energy by : Kazuharu Bamba
Download or read book Cosmological Inflation, Dark Matter and Dark Energy written by Kazuharu Bamba and published by MDPI. This book was released on 2019-11-14 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Various cosmological observations support not only cosmological inflation in the early universe, which is also known as exponential cosmic expansion, but also that the expansion of the late-time universe is accelerating. To explain this phenomenon, the existence of dark energy is proposed. In addition, according to the rotation curve of galaxies, the existence of dark matter, which does not shine, is also suggested. If primordial gravitational waves are detected in the future, the mechanism for realizing inflation can be revealed. Moreover, there exist two main candidates for dark matter. The first is a new particle, the existence of which is predicted in particle physics. The second is an astrophysical object which is not found by electromagnetic waves. Furthermore, there are two representative approaches to account for the accelerated expansion of the current universe. One is to assume the unknown dark energy in general relativity. The other is to extend the gravity theory to large scales. Investigation of the origins of inflation, dark matter, and dark energy is one of the most fundamental problems in modern physics and cosmology. The purpose of this book is to explore the physics and cosmology of inflation, dark matter, and dark energy.
Book Synopsis New Worlds, New Horizons in Astronomy and Astrophysics by : National Research Council
Download or read book New Worlds, New Horizons in Astronomy and Astrophysics written by National Research Council and published by National Academies Press. This book was released on 2011-02-04 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Driven by discoveries, and enabled by leaps in technology and imagination, our understanding of the universe has changed dramatically during the course of the last few decades. The fields of astronomy and astrophysics are making new connections to physics, chemistry, biology, and computer science. Based on a broad and comprehensive survey of scientific opportunities, infrastructure, and organization in a national and international context, New Worlds, New Horizons in Astronomy and Astrophysics outlines a plan for ground- and space- based astronomy and astrophysics for the decade of the 2010's. Realizing these scientific opportunities is contingent upon maintaining and strengthening the foundations of the research enterprise including technological development, theory, computation and data handling, laboratory experiments, and human resources. New Worlds, New Horizons in Astronomy and Astrophysics proposes enhancing innovative but moderate-cost programs in space and on the ground that will enable the community to respond rapidly and flexibly to new scientific discoveries. The book recommends beginning construction on survey telescopes in space and on the ground to investigate the nature of dark energy, as well as the next generation of large ground-based giant optical telescopes and a new class of space-based gravitational observatory to observe the merging of distant black holes and precisely test theories of gravity. New Worlds, New Horizons in Astronomy and Astrophysics recommends a balanced and executable program that will support research surrounding the most profound questions about the cosmos. The discoveries ahead will facilitate the search for habitable planets, shed light on dark energy and dark matter, and aid our understanding of the history of the universe and how the earliest stars and galaxies formed. The book is a useful resource for agencies supporting the field of astronomy and astrophysics, the Congressional committees with jurisdiction over those agencies, the scientific community, and the public.
Book Synopsis Finite Inflation, Holography, and Dark Matter Annihilation by : Andrew Joseph Scacco
Download or read book Finite Inflation, Holography, and Dark Matter Annihilation written by Andrew Joseph Scacco and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis covers work on theoretical cosmology relating to inflation, de Sitter space, dark matter annihilation, and holography. A unifying feature of all these topics is that all of them occur in de Sitter space or focus on epochs of the Universe when the spacetime was close to de Sitter and that all of them have some connection to holography. Chapter 1 provides a pedagogical introduction to the fundamentals of cosmology, inflation, de Sitter space, dark matter annihilation and entanglement entropy. Chapter 2 covers the impact on the causal entropic principle of dark matter annihilation that we find to have the greatest relevance at late times in the future when the dark energy has driven the universe to be asymptotically de Sitter. In this chapter we estimate holographically preferred dark matter properties for a range of assumptions. Chapter 3 covers holographic bounds in models of finite inflation, specifically the Banks-Fischler [3] bound and de Sitter equilibrium [4-6]. The assumptions in each of these models are explored in detail and some interesting new connections are presented. Chapter 4 tests models of inflation with a fast-roll start that happen to satisfy the holographic bounds in Chapter 3 against cosmic microwave background data from Planck. We find a slight preference for a feature at the scale predicted in [3] though this preference is not found to be statistically significant. Chapter 5 contains a numerical computation of the holographic mutual information for an annular configuration of regions on a conformal field theory in de Sitter space using the AdS/CFT correspondence. This computation shows that the de Sitter space CFT entanglement entropy matches what would be expected from a Minkowski CFT and shows that the HRT conjecture works for this case.
Book Synopsis New Limits on Dark Matter Annihilation from AMS Cosmic Ray Positron Data by :
Download or read book New Limits on Dark Matter Annihilation from AMS Cosmic Ray Positron Data written by and published by . This book was released on 2013 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Invisible Universe, The: Dark Matter, Dark Energy, And The Origin And End Of The Universe by : Antonino Del Popolo
Download or read book Invisible Universe, The: Dark Matter, Dark Energy, And The Origin And End Of The Universe written by Antonino Del Popolo and published by World Scientific. This book was released on 2021-04-20 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes some of the frontier problems of cosmology: our almost total ignorance of what the Universe is made up of, the mystery of its origin and its end. The book starts with a description of the historical events that led to the construction of the Big Bang model together with the stages that transformed the Universe from a very hot place to a very cold one, full with the structures that we observe today. These structures (stars, galaxies, etc.) constitute only 5% of the contents of the Universe. Concerning the remaining 95%, dubbed dark matter and dark energy, we know very little, and we have only indirect evidence of their existence. The text describes the story and the protagonists who showed the need for the existence of this 'missing matter', the observations, and puzzles they had to solve to understand that dark matter was not ordinary matter. The book describes the hunt for dark matter, carried out with instruments operating in space, on the Earth's surface, and in laboratories built in the bowels of the Earth. It also describes dark energy, which manifests itself in the accelerated expansion of the Universe, and appeared only a few billions of years ago. The book discusses why dark energy must exist and what its existence implies, especially for the future and the end of our Universe.
Download or read book Cosmology written by Steven Weinberg and published by Oxford University Press, USA. This book was released on 2008-02-21 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a uniquely comprehensive and detailed treatment of the theoretical and observational foundations of modern cosmology, by a Nobel Laureate in Physics. It gives up-to-date and self contained accounts of the theories and observations that have made the past few decades a golden age of cosmology.
Book Synopsis The Cosmic Cocktail by : Katherine Freese
Download or read book The Cosmic Cocktail written by Katherine Freese and published by Princeton University Press. This book was released on 2016-05-17 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: The inside story of the epic quest to solve the mystery of dark matter The ordinary atoms that make up the known universe—from our bodies and the air we breathe to the planets and stars—constitute only 5 percent of all matter and energy in the cosmos. The rest is known as dark matter and dark energy, because their precise identities are unknown. The Cosmic Cocktail is the inside story of the epic quest to solve one of the most compelling enigmas of modern science—what is the universe made of?—told by one of today's foremost pioneers in the study of dark matter. Blending cutting-edge science with her own behind-the-scenes insights as a leading researcher in the field, acclaimed theoretical physicist Katherine Freese recounts the hunt for dark matter, from the discoveries of visionary scientists like Fritz Zwicky—the Swiss astronomer who coined the term "dark matter" in 1933—to the deluge of data today from underground laboratories, satellites in space, and the Large Hadron Collider. Theorists contend that dark matter consists of fundamental particles known as WIMPs, or weakly interacting massive particles. Billions of them pass through our bodies every second without us even realizing it, yet their gravitational pull is capable of whirling stars and gas at breakneck speeds around the centers of galaxies, and bending light from distant bright objects. Freese describes the larger-than-life characters and clashing personalities behind the race to identify these elusive particles. Many cosmologists believe we are on the verge of solving the mystery. The Cosmic Cocktail provides the foundation needed to fully fathom this epochal moment in humankind’s quest to understand the universe.
Book Synopsis Particle Dark Matter by : Gianfranco Bertone
Download or read book Particle Dark Matter written by Gianfranco Bertone and published by Cambridge University Press. This book was released on 2010-01-07 with total page 763 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes the dark matter problem in particle physics, astrophysics and cosmology for graduate students and researchers.
Download or read book Dark Matter written by Michael Smith and published by BoD – Books on Demand. This book was released on 2022-07-06 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents several new, important explanations for dark matter, all dissimilar to the discredited subatomic particle-like but invisible matter. One chapter presents evidence that abundant cold hydrogen, baryonic matter, is the source of the missing gravity. Another chapter suggests that dark matter is better explained by stars in spiral galaxies that follow non-Keplerian orbits. A third chapter proposes that gravity attributed to dark matter is due to the sprinkling of black holes throughout galaxies, which is supported by LIGO/Virgo observations. Another chapter questions the assumptions of the Friedmann (FLRW) model, proposing a better method for handling astrophysical data. Additional chapters discuss cosmic ray propagation, axion decay, the cosmological scale factor, and the philosophical outlook of cosmologists when dealing with the questions of dark matter and dark energy.
Download or read book First Light written by Emma Chapman and published by Bloomsbury Publishing. This book was released on 2020-11-26 with total page 305 pages. Available in PDF, EPUB and Kindle. Book excerpt: Astronomers have successfully observed a great deal of the Universe's history, from recording the afterglow of the Big Bang to imaging thousands of galaxies, and even to visualising an actual black hole. There's a lot for astronomers to be smug about. But when it comes to understanding how the Universe began and grew up we are literally in the dark ages. In effect, we are missing the first one billion years from the timeline of the Universe. This brief but far-reaching period in the Universe's history, known to astrophysicists as the 'Epoch of Reionisation', represents the start of the cosmos as we experience it today. The time when the very first stars burst into life, when darkness gave way to light. After hundreds of millions of years of dark, uneventful expansion, one by the one these stars suddenly came into being. This was the point at which the chaos of the Big Bang first began to yield to the order of galaxies, black holes and stars, kick-starting the pathway to planets, to comets, to moons, and to life itself. Incorporating the very latest research into this branch of astrophysics, this book sheds light on this time of darkness, telling the story of these first stars, hundreds of times the size of the Sun and a million times brighter, lonely giants that lived fast and died young in powerful explosions that seeded the Universe with the heavy elements that we are made of. Emma Chapman tells us how these stars formed, why they were so unusual, and what they can teach us about the Universe today. She also offers a first-hand look at the immense telescopes about to come on line to peer into the past, searching for the echoes and footprints of these stars, to take this period in the Universe's history from the realm of theoretical physics towards the wonder of observational astronomy.
