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Self Interacting Dark Matter In Cosmological Simulations
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Book Synopsis Self-interacting Dark Matter in Cosmological Simulations by : Alexander Bastidas Fry
Download or read book Self-interacting Dark Matter in Cosmological Simulations written by Alexander Bastidas Fry and published by . This book was released on 2015 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: Self-Interacting Dark Matter is a cosmologically consistent alternative theory to Cold Dark Matter that solves problems of the Cold Dark Matter model on small scales. Our N-body simulations demonstrate that Self-Interacting Dark Matter creates constant density cores that are consistent with observations of Local Group dwarf galaxies. However, the apparent problems of Cold Dark Matter have natural astrophysical contributions from baryonic supernovae feedback. The evidence for Self-Interacting Dark Matter taken together with the evidence for the need for better feedback models presents a challenging environment in which to place constraints on either. We use high resolution cosmological simulations to compare the detailed properties of galaxies at a range of masses with a focus on dwarf galaxies which are the most dark matter dominated galaxies in the universe. We conclude that it is possible that velocity dependent Self-Interacting Dark Matter could explain the common mass scale of dark matter on small scales, the too big to fail problem, and the core versus cusp problem even in the absence of strong stellar feedback; however, baryonic processes offer solutions to these same problems. We find that once baryon physics and outflows are introduced, cores are created in both Self-Interacting Dark Matter and Cold Dark Matter cosmologies.
Book Synopsis Constraints on Dark Matter and Milky Way Satellite Galaxies from Cosmological Simulations by : Miguel Eduardo Rocha Gaso
Download or read book Constraints on Dark Matter and Milky Way Satellite Galaxies from Cosmological Simulations written by Miguel Eduardo Rocha Gaso and published by . This book was released on 2014 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cosmological simulations describing the non-linear evolution of dark matter structures in the Universe have become an indispensable tool to study the predictions made by our standard model of cosmology, and to confront them with observations. In this thesis I present a new idea for using cosmological simulations to infer the accretion times of Milky Way satellite galaxies from their observed positions and kinematics. We find that Carina, Ursa Minor, and Sculptor were all accreted early, more than 8 Gyr ago. Five other dwarfs, including Sextans and Segue 1, are also probable early accreters, though with larger uncertainties. On the other extreme, Leo T is just falling into the Milky Way for the first time while Leo I fell ~2 Gyr ago and is now climbing out of the Milky Way's potential after its first perigalacticon. The energies of several other dwarfs, including Fornax and Hercules, point to intermediate infall times, 2 - 8 Gyr ago. Our analysis suggests that the Large Magellanic Cloud crossed inside the Milky Way virial radius recently, within the last ~4 billion years. Also I present new constrains on how strongly dark matter particles can interact with themselves. For this we use a set cosmological simulations that implement a new self-consistent algorithm to treat dark matter self-interactions. We find that self-interacting dark matter models with cross sections in the order [sigma]/m ~ 0.5 cm2 /g ~ 1 barn/GeV would be capable of reproducing the observed core sizes and central densities of dark matter halos in a wide range of scales, from tiny dwarf galaxies to large galaxy clusters, without violating any other observational constraints. Higher resolution simulations over a wider range of masses and properly accounting for the effects of baryonic processes that are not yet included in our simulation will be required to confirm our expectations and place better constraints. I discuss our plans for achieving this goal and show some preliminary results from a new set of simulations.
Book Synopsis Constraining Dark Matter Physics with Cosmological Simulations by : Oliver D. Elbert
Download or read book Constraining Dark Matter Physics with Cosmological Simulations written by Oliver D. Elbert and published by . This book was released on 2017 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dark Matter (DM) accounts for the vast majority of mass in the universe, but the particle identity of dark matter remains a mystery. Uncovering the fundamental nature of DM remains one of the greatest challenges facing modern physics. Because the only information about DM comes from astrophysical observations, these are the best sources to constrain models. Dwarf galaxies present an especially tantalizing regime to investigate dark physics, as they have the highest ratio of dark to luminous matter and therefore will be most affected by differences between DM models. Additionally, this is precisely the scale where generic dark matter theories have the most difficulty reproducing astronomical observations, leading to the missing satellites, core-cusp and too-big-to-fail (TBTF) problems.A particular class of models with nuclear scale self-interactions (called SIDM) has emerged as a promising candidate. SIDM naturally forms cored halos, which may alleviate both the core-cusp and TBTF problems. However, at larger scales the the interplay between SIDM halos and the galaxies residing in them is poorly understood, complicating this picture greatly. In this thesis I present numerical simulations of SIDM and CDM halos investigating these issues. I show that at dwarf scales SIDM cross sections as small as 0.5cm2 g--1 solve the TBTF and core-cusp problems, and that cross sections 2 orders of magnitude larger are not ruled out. I have also embedded gravitational potentials that approximate realistic galaxies in simulations of larger haloes in order to test the impact of galaxy formation on SIDM halos. These simulations show that SIDM is indistinguishable from CDM in systems where the galaxy dominates the central region, but in galaxies with higher mass-to-light ratios or less centrally concentrated baryons it is possible to constrain SIDM cross sections. In the galaxy cluster regime I show that an SIDM cross section of $0.1-0.2 cm2 g --1 is preferred to CDM or other SIDM cross sections.
Book Synopsis Sources and Detection of Dark Matter and Dark Energy in the Universe by : David B. Cline
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.
Book Synopsis An Introduction To Particle Dark Matter by : Stefano Profumo
Download or read book An Introduction To Particle Dark Matter written by Stefano Profumo and published by World Scientific Publishing Company. This book was released on 2017-02-23 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: What is the dark matter that fills the Universe and binds together galaxies? How was it produced? What are its interactions and particle properties?The paradigm of dark matter is one of the key developments at the interface of cosmology and elementary particle physics. It is also one of the foundations of the standard cosmological model. This book presents the state of the art in building and testing particle models for dark matter. Each chapter gives an analysis of questions, research directions, and methods within the field. More than 200 problems are included to challenge and stimulate the reader's knowledge and provide guidance in the practical implementation of the numerous 'tools of the trade' presented. Appendices summarize the basics of cosmology and particle physics needed for any quantitative understanding of particle models for dark matter.This interdisciplinary textbook is essential reading for anyone interested in the microscopic nature of dark matter as it manifests itself in particle physics experiments, cosmological observations, and high-energy astrophysical phenomena: from graduate students and advanced undergraduates to cosmologists and astrophysicists interested in particle models for dark matter and particle physicists interested in early-universe cosmology and high-energy astrophysics.
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 Probing Local Group Galactic Substructure with Cosmological Simulations by : Gregory Alan Dooley
Download or read book Probing Local Group Galactic Substructure with Cosmological Simulations written by Gregory Alan Dooley and published by . This book was released on 2017 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Lambda cold dark matter (ACDM) model is enormously successful at predicting large scale structure in the Universe. However, some tensions still remain on small scales, specifically regarding observed satellites of the Milky Way (MW) and Andromeda. Foremost among the problems have been the missing satellite, too big to fail, and cusp/core problems, which concern the expected abundance of satellites and their inner structure. This Ph.D. thesis consists of a series of studies using dark matter only cosmological N-body simulations of MW-mass galaxies to address topics related to these issues. In light of the recent Planck mission, I investigate how changes to cosmological parameters affect dark matter halo substructure. I find that the process of continuous sub-halo accretion and destruction leads to a steady state description of most subhalo properties in a given host, unchanged by small fluctuations in cosmological parameters. Subhalo concentration, maximum circular velocity, and formation times, however, are somewhat affected. One way to reduce the central density of satellites, as needed to solve the cusp/core and too big to fail problems, is through self-interacting dark matter (SIDM). I search for new implications of SIDM and find that stars in satellites spread out to larger radii and are tidally stripped at a higher rate in SIDM than CDM, even though the mass loss rate of dark matter is unchanged. These signatures should be particularly prominent in ultrafaint dwarf galaxies for the class of otherwise difficult to constrain velocity-dependent SIDM models. I also helped carry out the Caterpillar project, a suite of 36 high mass resolution (~ 10' Mo/particle) simulations of MW-like galaxies used to study diversity in halo substructure. To these, I apply abundance matching and reionization models to make novel predictions about the abundance of satellites in isolated dwarf galaxies out to 8 Mpc to help guide future searches. Applying the same techniques to predict satellites within 50 kpc of the LMC, I discover large discrepancies with the observed stellar mass function, which may lead to new constraints on the galaxy stellar mass-halo mass relationship, and the ability of reionization to leave dark matter halos entirely dark.
Book Synopsis SIDM on Fire: Hydrodynamical Self-interacting Dark Matter Simulations of Low-mass Dwarf Galaxies by :
Download or read book SIDM on Fire: Hydrodynamical Self-interacting Dark Matter Simulations of Low-mass Dwarf Galaxies written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis N-body Simulations of Self-interacting Dark Matter with a Velocity-dependent Cross Section by : Lenard Kasselmann
Download or read book N-body Simulations of Self-interacting Dark Matter with a Velocity-dependent Cross Section written by Lenard Kasselmann and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Dark Matter in the Universe by : Società italiana di fisica
Download or read book Dark Matter in the Universe written by Società italiana di fisica and published by IOS Press. This book was released on 1996 with total page 739 pages. Available in PDF, EPUB and Kindle. Book excerpt: Physics and astrophysics came to dark matter through many different routes, finally accepting it, but often with some distaste. It has been noticed that the existence of dark matter is yet another displacement of humans from the centre of the Universe: not only do our planet and our sun have no central position in the Universe, not only are humans just animals (although with a 'specialized' central nervous system), but even the material of which we are made is only a marginal component of the cosmic substance! If this is the right attitude to take, scientists feeling distaste for dark matter are much like Galileo Galilei's colleagues who refused to look through the telescope to watch the Medici planets. Nevertheless, astronomers, when required to take a ballot in favour of some cosmological model, often still vote for 'pure baryonic' with substantial majorities, although most cosmologists assume that a 'cold' component of dark matter plays a role in producing the world as we observe it. Among the many subjects covered by the book, particular emphasis was given to 1) summarizing the current status of the observations both of the distribution of the nearby galaxies and of the evolution of more distant galaxies; 2) advanced statistical techniques for quantifying structure in galaxy redshift and peculiar velocity surveys; 3) the art of cosmic inflation and models for dark matter candidates, and their implications for cosmic microwave background observations; 4) implications of cold dark matter variants for large scale structure, as worked out both by quasi-linear techniques and by fully nonlinear simulations; and 5) Eulerian and Lagrangian approximations for treating the nonlinear dynamics.
Download or read book Beyond ΛCDM written by Sownak Bose and published by Springer. This book was released on 2018-08-02 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book employs computer simulations of ‘artificial’ Universes to investigate the properties of two popular alternatives to the standard candidates for dark matter (DM) and dark energy (DE). It confronts the predictions of theoretical models with observations using a sophisticated semi-analytic model of galaxy formation. Understanding the nature of dark matter (DM) and dark energy (DE) are two of the most central problems in modern cosmology. While their important role in the evolution of the Universe has been well established—namely, that DM serves as the building blocks of galaxies, and that DE accelerates the expansion of the Universe—their true nature remains elusive. In the first half, the authors consider ‘sterile neutrino’ DM, motivated by recent claims that these particles may have finally been detected. Using sophisticated models of galaxy formation, the authors find that future observations of the high redshift Universe and faint dwarf galaxies in the Local Group can place strong constraints on the sterile neutrino scenario. In the second half, the authors propose and test novel numerical algorithms for simulating Universes with a ‘modified’ theory of gravity, as an alternative explanation to accelerated expansion. The authors’ techniques improve the efficiency of these simulations by more than a factor of 20 compared to previous methods, inviting the readers into a new era for precision cosmological tests of gravity.
Book Synopsis Essentials on Dark Matter by : Abraao Jesse Capistrano
Download or read book Essentials on Dark Matter written by Abraao Jesse Capistrano and published by BoD – Books on Demand. This book was released on 2018-09-12 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: The modern roots on the dark matter problem were basically launched in the 30s, with Zwicky's observations on a notorious discrepancy of mass in coma cluster that presented 500 times the mass than expected using the Newtonian theory (Virial theorem). Curiously, almost 90 years have passed, and the dark matter problem persists and is one of the most common challenges in both observational and theoretical physics. The Dark Matter is a rapid communication on the status-quo of the dark matter phenomenology as well as a presentation of new discussions on the theme.
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: Dark matter is among the most important open problems in modern physics. Aimed at graduate students and researchers, this book describes the theoretical and experimental aspects of the dark matter problem in particle physics, astrophysics and cosmology. Featuring contributions from 48 leading theorists and experimentalists, it presents many aspects, from astrophysical observations to particle physics candidates, and from the prospects for detection at colliders to direct and indirect searches. The book introduces observational evidence for dark matter along with a detailed discussion of the state-of-the-art of numerical simulations and alternative explanations in terms of modified gravity. It then moves on to the candidates arising from theories beyond the Standard Model of particle physics, and to the prospects for detection at accelerators. It concludes by looking at direct and indirect dark matter searches, and the prospects for detecting the particle nature of dark matter with astrophysical experiments.
Book Synopsis Simulations of Dark Matter with Frequent and Rare Self-interactions by : Moritz Serenus Fischer
Download or read book Simulations of Dark Matter with Frequent and Rare Self-interactions written by Moritz Serenus Fischer and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Role of Halo Substructure in Gamma-Ray Dark Matter Searches by : Miguel A. Sánchez-Conde
Download or read book The Role of Halo Substructure in Gamma-Ray Dark Matter Searches written by Miguel A. Sánchez-Conde and published by MDPI. This book was released on 2020-05-28 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: An important, open research topic today is to understand the relevance that dark matter halo substructure may have for dark matter searches. In the standard cosmological model, halo substructure or subhalos are predicted to be largely abundant inside larger halos, for example, galaxies such as ours, and are thought to form first and later merge to form larger structures. Dwarf satellite galaxies—the most massive exponents of halo substructure in our own galaxy—are already known to be excellent targets for dark matter searches, and indeed, they are constantly scrutinized by current gamma-ray experiments in the search for dark matter signals. Lighter subhalos not massive enough to have a visible counterpart of stars and gas may be good targets as well, given their typical abundances and distances. In addition, the clumpy distribution of subhalos residing in larger halos may boost the dark matter signals considerably. In an era in which gamma-ray experiments possess, for the first time, the exciting potential to put to test the preferred dark matter particle theories, a profound knowledge of dark matter astrophysical targets and scenarios is mandatory should we aim for accurate predictions of dark matter-induced fluxes for investing significant telescope observing time on selected targets and for deriving robust conclusions from our dark matter search efforts. In this regard, a precise characterization of the statistical and structural properties of subhalos becomes critical. In this Special Issue, we aim to summarize where we stand today on our knowledge of the different aspects of the dark matter halo substructure; to identify what are the remaining big questions, and how we could address these; and, by doing so, to find new avenues for research.
Book Synopsis Faint Galaxies and Small Halos by : Ethan Oliver Nadler
Download or read book Faint Galaxies and Small Halos written by Ethan Oliver Nadler and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis addresses the intersection of dark matter and galaxy formation physics by modeling the faintest galaxies in the Universe in a cosmological context. In the first part of this work, I present an empirical model for the connection between faint galaxies and small dark matter halos. Combining this model with tailored cosmological simulations of Milky Way analogs and state-of-the-art satellite galaxy observations yields new insights into dwarf galaxy formation and hierarchical structure formation. Next, I show that these same dwarf galaxy observations place stringent constraints on microphysical dark matter properties including its warmth, self-interactions, Standard Model interactions, minimum particle mass, and formation epoch. Finally, I describe a unified framework that combines dark matter constraints from dwarf galaxies and strong gravitational lensing, paving the way for next-generation surveys of small-scale cosmic structure to deliver unprecedented insights into dark matter physics.
Book Synopsis Cosmological Simulations of Dark Matter Halos by : Darren S. Reed
Download or read book Cosmological Simulations of Dark Matter Halos written by Darren S. Reed and published by . This book was released on 2003 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt:
