Simulating Structure Formation with Ultra-light Bosonic Dark Matter PDF Download

Author: Bodo Schwabe
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Despite being a cornerstone of the standard model of cosmology, the exact nature of dark matter (DM) remains unknown. The lack of evidence for weakly interacting massive particles that could constitute DM is generating increasing interest in alternative candidates. These include the theoretically well-motivated QCD axion, which solves the strong CP problem, and axion-like particles generically arising in string theories. This thesis focuses on the latter. If non-gravitational interactions can be neglected, this form of DM is known as fuzzy dark matter (FDM). While indistinguishable from col...

Author: Jan Veltmaat
Publisher:
ISBN:
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Languages : en
Pages : 0

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Ultralight bosonic particles forming a coherent state are dark matter candidates with distinctive wave-like behaviour on the scale of dwarf galaxies and below. In this thesis, a new simulation technique for ultralight bosonic dark matter, also called fuzzy dark matter, is developed and applied in zoom-in simulations of dwarf galaxy halos. When gas and star formation are not included in the simulations, it is found that halos contain solitonic cores in their centers reproducing previous results in the literature. The cores exhibit strong quasi-normal oscillations, which are possibly testable...

Author: Derek F. Jackson Kimball
Publisher: Springer Nature
ISBN: 3030958523
Category : Science
Languages : en
Pages : 375

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Book Description
A host of astrophysical measurements suggest that most of the matter in the Universe is an invisible, nonluminous substance that physicists call “dark matter.” Understanding the nature of dark matter is one of the greatest challenges of modern physics and is of paramount importance to our theories of cosmology and particle physics. This text explores one of the leading hypotheses to explain dark matter: that it consists of ultralight bosons forming an oscillating field that feebly interacts with light and matter. Many new experiments have emerged over the last decade to test this hypothesis, involving state-of-the-art microwave cavities, precision nuclear magnetic resonance (NMR) measurements, dark matter “radios,” and synchronized global networks of atomic clocks, magnetometers, and interferometers. The editors have gathered leading experts from around the world to present the theories motivating these searches, evidence about dark matter from astrophysics, and the diverse experimental techniques employed in searches for ultralight bosonic dark matter. The text provides a comprehensive and accessible introduction to this blossoming field of research for advanced undergraduates, beginning graduate students, or anyone new to the field, with tutorials and solved problems in every chapter. The multifaceted nature of the research – combining ideas and methods from atomic, molecular, and optical physics, nuclear physics, condensed matter physics, electrical engineering, particle physics, astrophysics, and cosmology – makes this introductory approach attractive for beginning researchers as well as members of the broader scientific community. This is an open access book.

Author: Victoriano Carmona
Publisher: Springer
ISBN: 3319667661
Category : Science
Languages : en
Pages : 428

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This book is part of a two volume set which presents the analysis of nonlinear phenomena as a long-standing challenge for research in basic and applied science as well as engineering. It discusses nonlinear differential and differential equations, bifurcation theory for periodic orbits and global connections. The integrability and reversibility of planar vector fields and theoretical analysis of classic physical models are sketched. This first volume concentrates on the mathematical theory and computational techniques that are essential for the study of nonlinear science, a second volume deals with real-world nonlinear phenomena in condensed matter, biology and optics.

Author: Claudia Moreno González
Publisher: Springer Science & Business Media
ISBN: 3319020633
Category : Science
Languages : en
Pages : 223

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Proceedings from the 2012 Fourth International Meeting on Gravitation and Cosmology, focusing on accelerated cosmic expansion This volume provides both an update and a review of the state of alternative theories of gravity in connection with the accelerated expansion of the universe issue. Different theoretical proposals exist to explain the acceleration in the cosmic expansion, generating the dark energy issue and opening the possibility to theories of gravity alternative to general relativity. Related issues such as the dark matter problem are also surveyed in order to give the readers profound insight on the subject from different points of view. Comprised of short talks and plenary lectures given by leading experts in the field, some of them with brilliant and historic contributions, the book allows the reader to find readable and referenced surveys in topics like f(R) theories, the dark matter and dark energy issues, Modified Newtonian Dynamics (MOND) scenarios, f(T) theories, scalar-tensor theories derived from non-Riemannian geometries, emergent universes, the cosmological constant and other topics of current interest for younger and senior physicists and graduate students. These proceedings are from the Fourth International Meeting on Gravitation and Cosmology, held in Guadalajara, Jalisco, México, from 20 - 25 May, 2012, was sponsored by ICTP- Trieste, Italy and COECyTJAL-Universidad de Guadalajara, México. This event is a series of scientific meetings started in 2004 in Cuba, focusing on current and selected topics in the fields of gravitation and cosmology.

Author: Xiaolong Du
Publisher:
ISBN:
Category :
Languages : en
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Ultralight axion is a scalar field with an extremely small mass $\sim10^{-22} eV$. It is proposed as an alternative dark matter candidate to the standard cold dark matter (CDM). If self-interactions between axions can be ignored, it is also called fuzzy dark matter (FDM). On large scales, FDM behaves like CDM producing large scale structure of the Universe consistent with current observations. But on scales below the Jeans length, quantum pressure arising from coherent oscillations of the scalar filed counters gravity, leading to a large suppression in the structure formation and cored dark...

Author: Carlos Chover Lopez
Publisher:
ISBN:
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Languages : en
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In the last century, new observational techniques and discoveries such as the Cosmic Microwave Background Radiation have brought a new dimension of knowledge about the Universe. Therefore new theories and models have been proposed to explain the observed Universe. Computer simulations are a very important tool because they lay a bridge between theory, often over-simpli ed, and observations, which reveal the complexity of our Universe. In this thesis, it is given a review of observations including the most important discoveries and results that help to describe the Universe and have been used to develop the models considered nowadays. The cosmological theory behind the large-scale structure formation is explained, from the basis of the Friedman model to the formation of structures through the linear, quasi-linear and non-linear regime, including the Zeldovich approximation and the spherical collapse model. Furthermore, the di erent types of codes used for cosmological simulations are introduced, focusing on the N-body codes and presenting the code used in this thesis, developed by Klypin & Holtzman (1997). The tools used to analyse the results: density plots, power spectrum and mass variance are described as well. Three main sets of simulations have been performed: a basic simulation (RUN0) with standard cosmological parameters, simulations of CDM and simulations of Hot+Cold Dark Matter (HCDM). All the simulations use 323 particles, while di erent cosmological parameters have been changed e.g. 8, m, and n. Thus, it is observed that higher values of m and low values of lead to more clustering and hence more developed structures. Moreover, the e ect of 8 appears to be critical, since it determines the amplitude of the density uctuations at the initial redshift of the simulation. When studying the presence of hot dark matter, the main di erence comes from the cut-o in the power spectrum due to the hot dark matter free-streaming, resulting in less developed structures. Similarly to the previous case, the e ects of the cosmological parameters are explained for this model. Finally, some additional simulations regarding dark halos populations and density pro- les are included in the Appendix.

Author: Jiajun Chen
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Dark matter is a hypothetical form of matter, which is thought to make up nearly $27 %$ of the contents in our Universe. An increasingly popular idea is that the dark matter could be composed of light (pseudo-)scalar particles with large occupation number so that they can be described by a classical scalar field $ phi$, with the mass $ approx 10^{-22}$eV. As the finite energy ground state solutions for such a field, boson stars are a good subject in the study of dark matter. In this dissertation, the primary focus is on boson stars and their surrounding miniclusters. Firstly, using my new a...

Author: Nicos Hiotelis
Publisher:
ISBN: 9781608764730
Category : Science
Languages : en
Pages : 0

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Book Description
This book is aimed at helping those that are interested in learning about some of the analytical methods used for the study of the formation of dark matter structures in the Universe. The development of analytical or semi-numerical methods for the very interesting problem of structure formation is a very active research area. Analytical methods -compared to N-body simulations- are very economical and give more light to the physical mechanisms during the process of formation. In spite of focusing on a very specific problem this book is not self-contained. Cosmological models are briefly discussed, and only flat models with a cosmological constant. The history of the Universe up to the epoch which gravity plays the main role in the evolution is also not discussed. Fortunately, classical books of Cosmology are available for the reader who is interested in these subjects. The emphasis of this book is on specific problems such as the mass growth, the density profiles and the random angular momentum of DMH.

Author: Felix Stoehr
Publisher: Sudwestdeutscher Verlag Fur Hochschulschriften AG
ISBN: 9783838108841
Category :
Languages : en
Pages : 212

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Book Description
In this work we use the N-body resimulation technique to address aspects of structure formation. In the first chapter we study the influence of the local environment of DM haloes on their properties. In the second chapter we address the so-called "substructure problem" which is one of the major challenges of the CDM model of cosmology. We perform ultra-high resolution simulations of the assembly of a Milky Way type dark matter halo within its full cosmological context and propose a new analytical fitting formula (SWTS) which provides a better fit to the simulated Milky Way halo than the NFW or Moore profiles do. In the third chapter we use our ultra-high resolution simulations to study the possible -ray signal from dark matter annihilation. If such a signal was detected, the nature of the dark matter, the answer to one of the most important questions of modern cosmology, would be known. (urn: nbn: de: bvb:19-16446)"