Author: Silvia GalliPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Constraining the Thermal History of the Universe with the Cosmic Microwave Background
Author: Silvia GalliConstraining the Thermal History of the Universe with the Cosmic Microwave Background
Author: Silvia GalliPublisher:
ISBN:
Category :
Languages : en
Pages : 241
Book Description
The excellent agreement between the Standard Model of Cosmology and the recent measurements of the Cosmic Microwave Background (CMB) permits to constrain a wide range of physical processes. In particular, in this thesis we exploit the remarkable agreement between the theoretical description of the recombination process, occurring at z~1000, and the CMB data to severely constrain phenomena that affect the evolution of the thermal history of the universe. This contributes answering some important issues still unsolved in the standard model of cosmology. We first address the problem of the nature of dark matter. An extra energy injection due to dark matter annihilation during the epoch of recombination would affect the shape of the CMB power spectra. This allows to constrain dark matter properties using the CMB. The second question regards the validity of conventional physics to describe the Universe. New fundamental theories might predict the space-time variation of fundamental 'constants'. In this thesis we test the constancy of the gravitational constant and of the fine structure constant using the CMB. The third question concerns the characteristics (and in particular, the evolution) of dark energy. The information that can be extracted from the CMB is limited, making necessary the use of complementary probes that can break degeneracies between parameters. This is the case for the evolution of the dark energy equation of state with time, that the CMB can only weakly constrain. We thus show how the observation of clusters of galaxies combined with CMB can be a powerful tool to constrain dark energy.
The Cosmic Microwave Background
Author: Slobodan PerovicPublisher: Cambridge University Press
ISBN: 110884460X
Category : Science
Languages : en
Pages : 217
Book Description
Explanations of the cosmic microwave background prompt this unique case study of theory building in modern science.
Constraining the Epoch of Recombination with Recent Observations of the Cosmic Microwave Background
Author: Angela M. LinnPublisher:
ISBN:
Category : Cosmic background radiation
Languages : en
Pages :
Book Description
Abstract: The radiation in the Cosmic Microwave Background (CMB) last scattered off of matter during the epoch of recombination, when nuclei captured electrons for the first time, and its predicted anisotropy power spectra are sensitive to the details of recombination. In light of recent high quality observations of the CMB, it is worthwhile to re-examine the constraints that can be placed on recombination. We use a very general extension to the standard model of recombination characterized by two parameters, a and b, which multiply the overall rates of recombination and ionization and the binding energies of hydrogen respectively. We utilize WMAP temperature and TE cross-correlation data, along with temperature data at smaller scales from ACBAR and CBI, to place constraints on these parameters. The range of recombination histories which are the best match to the data fall within the range -0.4
The Music of the Big Bang
Author: Amedeo BalbiPublisher: Springer Science & Business Media
ISBN: 3540787283
Category : Science
Languages : en
Pages : 167
Book Description
Ever since its infancy, humankind has been seeking answers to some very basic and profound questions. Did the Universe begin? If it did, how old is it, and where did it come from? What is its shape? What is it made of? Fascinating myths and brilliant in- itions attempting to solve such enigmas can be found all through the history of human thought. Every culture has its own legends, itsownworldcreationtales,itsphilosophicalspeculations,itsre- gious beliefs. Modern science, however, cannot content itself with fanciful explanations, no matter how suggestive they are. No- days, our theories about the Universe, built upon rational ded- tion, have to survive the hard test of experiment and observation. Cosmology, the science which studies the origin and evo- tion of the Universe, had to overcome enormous dif?culties before it could achieve the same level of dignity as other physical dis- plines. At ?rst, it had no serious physical model and mathematical tools that could be used to address the complexity of the problems it had to face. Then, it suffered from a chronic lack of experim- tal data, which made it almost impossible to test the theoretical speculations. Given this situation, answering rigorously the many questions on the nature of the Universe seemed nothing more than a delusion. Today, however, things have changed. We live in the golden age of cosmology: an exciting moment, when, for the ?rst time, we are able to scienti?cally understand our Universe.
The Early Universe and the Cosmic Microwave Background: Theory and Observations
Author: Norma G. SànchezPublisher: Springer Science & Business Media
ISBN: 9400710585
Category : Science
Languages : en
Pages : 583
Book Description
The goal of the Daniel Chalonge School on Astrofundamental Physics is to contribute to a theory of the universe (and particularly of the early universe) up to the marks, and at the scientific height of, the unprecedented accuracy, existent and expected, in the observational data. The impressive development of modern cosmology during the last decades is to a large extent due to its unification with elementary particle physics and quantum field theory. The cross-section between these fields has been increasing setting up Astrofundamental Physics. The early universe is an exceptional (theoretical and experimental) laboratory in this new discipline. This NATO Advanced Study Institute provided an up dated understanding, from a fundamental physics and deep point of view, of the progress and key issues in the early universe and the cosmic microwave background: theory and observations. The genuine interplay with large scale structure formation and dark matter problem were discussed. The central focus was placed on the cosmic microwave background. Emphasis was given to the precise inter-relation between fundamental physics and cosmology in these problems, both at the theoretical and experimental/observational levels, within a deep and well defined programme which provided in addition, a careful interdisciplinarity. Special sessions were devoted to high energy cosmic rays, neutrinos in astrophysics, and high energy astrophysics. Deep understanding, clarification, synthesis, careful interdisciplinarity within a fundamental physics framework, were the main goals of the course.
Origins of the Universe
Author: Keith CooperPublisher: Icon Books
ISBN: 1785786431
Category : Science
Languages : en
Pages : 123
Book Description
The quest to find a theory of quantum gravity that could potentially explain everything. Nearly 60 years ago, Nobel Prize-winners Arno Penzias and Robert Wilson stumbled across a mysterious hiss of faint radio static that was interfering with their observations. They had found the key to unravelling the story of the Big Bang and the origin of our universe. That signal was the Cosmic Microwave Background (CMB), the earliest light in the universe, released 379,000 years after the Big Bang. It contains secrets about what happened during the very first tiny increments of time, which had consequences that have rippled throughout cosmic history, leading to the universe of stars and galaxies that we live in today. This is the enthralling story of the quest to understand the CMB radiation and what it can tell us of the origins of time and space, from bubble universes to a cyclical cosmos - and possibly leading to the elusive theory of quantum gravity itself.
Constraining the Cosmic Microwave Background Temperature Evolution and the Population and Structure of Galaxy Llusters and Groups from the South Pole Telescope and the Planck Surveyor
Author: Jiayi LiuThe Cosmic Microwave Background
Author: Ruth DurrerPublisher: Cambridge University Press
ISBN: 1107135222
Category : Science
Languages : en
Pages : 519
Book Description
This graduate textbook describes the physics of the Cosmic Microwave Background, arguably the most important topic in modern cosmology.
Quantum Aspects of Black Holes
Author: Xavier CalmetPublisher: Springer
ISBN: 3319108522
Category : Science
Languages : en
Pages : 322
Book Description
Beginning with an overview of the theory of black holes by the editor, this book presents a collection of ten chapters by leading physicists dealing with the variety of quantum mechanical and quantum gravitational effects pertinent to black holes. The contributions address topics such as Hawking radiation, the thermodynamics of black holes, the information paradox and firewalls, Monsters, primordial black holes, self-gravitating Bose-Einstein condensates, the formation of small black holes in high energetic collisions of particles, minimal length effects in black holes and small black holes at the Large Hadron Collider. Viewed as a whole the collection provides stimulating reading for researchers and graduate students seeking a summary of the quantum features of black holes.