Introduction to Cosmology - Experimental Elementary Particle
... of our Galaxy is not known as accurately as the mass of the Sun; in round numbers, though, it is Mgal ≈ 1012 M¯ . The Sun, incidentally, also provides the standard unit of power used in astronomy. The Sun’s luminosity (that is, the rate at which it radiates away energy in the form of light) is 1 L¯ ...
... of our Galaxy is not known as accurately as the mass of the Sun; in round numbers, though, it is Mgal ≈ 1012 M¯ . The Sun, incidentally, also provides the standard unit of power used in astronomy. The Sun’s luminosity (that is, the rate at which it radiates away energy in the form of light) is 1 L¯ ...
PPT
... BBO will probe the frequency region of 0.01–10 Hz, a region between the measurement bands of the presently funded ground- and space-based detectors. Its primary goal is the study of primordial gravitational waves from the era of the big bang, at a frequency range not limited by the confusion noise f ...
... BBO will probe the frequency region of 0.01–10 Hz, a region between the measurement bands of the presently funded ground- and space-based detectors. Its primary goal is the study of primordial gravitational waves from the era of the big bang, at a frequency range not limited by the confusion noise f ...
Georges Lemaître, The beginning of the world from
... In short, the cosmological work of Lemaître was built in two phases. Initially, he found independently of Friedmann that the Einstein field equations of general relativity admitted non-static cosmological solutions. At the same time, he took into account the observations on the recession velocity of ...
... In short, the cosmological work of Lemaître was built in two phases. Initially, he found independently of Friedmann that the Einstein field equations of general relativity admitted non-static cosmological solutions. At the same time, he took into account the observations on the recession velocity of ...
Invited Review The Beginning and Evolution of the Universe
... be the consequence of a simple inflationary infancy of the Universe—a very early period of extremely rapid expansion, which stretched zero-point quantum-mechanical fluctuations to larger length scales and transmuted them into the needed classical inhomogeneities in the mass-energy distribution. At t ...
... be the consequence of a simple inflationary infancy of the Universe—a very early period of extremely rapid expansion, which stretched zero-point quantum-mechanical fluctuations to larger length scales and transmuted them into the needed classical inhomogeneities in the mass-energy distribution. At t ...
attached file
... Before we discuss which of these three pictures describe our universe (if any) we must make a few disclaimers: Because the universe has a finite age (~13.7 billion years) we can only see a finite distance out into space: ~13.7 billion light years. This is our so-called horizon. The Big Bang Model do ...
... Before we discuss which of these three pictures describe our universe (if any) we must make a few disclaimers: Because the universe has a finite age (~13.7 billion years) we can only see a finite distance out into space: ~13.7 billion light years. This is our so-called horizon. The Big Bang Model do ...
Inflation and the Cosmic Microwave Background
... further into the past it curves in and makes a teardrop shape. This is a fundamental feature of the expanding universe; the furthest light that we can see now was receding from us for the rst few billion years of its voyage. The Hubble sphere, particle horizon, event horizon and past light cone are ...
... further into the past it curves in and makes a teardrop shape. This is a fundamental feature of the expanding universe; the furthest light that we can see now was receding from us for the rst few billion years of its voyage. The Hubble sphere, particle horizon, event horizon and past light cone are ...
Cosmological solutions of the Einstein
... missing part making Ω = 1 complete is dark matter (cosmological constant 73%) and cold dark matter (what is it ? 23%). The strongly time and scenario dependent energy density ρ(t) easily deviates by 60 orders of magnitude from ρ0,crit today, given the evolution during the enormous time span of the p ...
... missing part making Ω = 1 complete is dark matter (cosmological constant 73%) and cold dark matter (what is it ? 23%). The strongly time and scenario dependent energy density ρ(t) easily deviates by 60 orders of magnitude from ρ0,crit today, given the evolution during the enormous time span of the p ...
Time After Time — Big Bang Cosmology and the Arrows
... also run in reverse. So why doesn’t it in our universe? This question could be rejected as meaningless if one argues like this: disorder increases with time because we measure time in the direction in which disorder increases. However, this does not solve the problem, because it would still remain u ...
... also run in reverse. So why doesn’t it in our universe? This question could be rejected as meaningless if one argues like this: disorder increases with time because we measure time in the direction in which disorder increases. However, this does not solve the problem, because it would still remain u ...
Advanced Topics in Cosmology: A Pedagogical Introduction
... baryons, dark matter, radiation, etc.) to the critical density. Observations then lead to the following results: (1) Our universe has 0.98 . Ωtot . 1.08. The value of Ωtot can be determined from the angular anisotropy spectrum of the cosmic microwave background radiation (CMBR; see Section VI) and t ...
... baryons, dark matter, radiation, etc.) to the critical density. Observations then lead to the following results: (1) Our universe has 0.98 . Ωtot . 1.08. The value of Ωtot can be determined from the angular anisotropy spectrum of the cosmic microwave background radiation (CMBR; see Section VI) and t ...
22_Testbank
... A) these forces are important only at temperatures below the freezing point of water–a temperature that the universe reached at an age of about 10-10 second. B) "freezing out" was a term coined by particle physicists who think that the Big Bang theory is really cool. C) prior to this time the electr ...
... A) these forces are important only at temperatures below the freezing point of water–a temperature that the universe reached at an age of about 10-10 second. B) "freezing out" was a term coined by particle physicists who think that the Big Bang theory is really cool. C) prior to this time the electr ...
APS Slide Presentation
... • Andrei Linde has described mathematically how quantum fluctuations could cause a big bang (The Inflationary Universe). While Linde’s proposal is probably the best contemporary explanation of what caused the Big Bang, there is no verifiable evidence that a spontaneous quantum fluctuation did so. Th ...
... • Andrei Linde has described mathematically how quantum fluctuations could cause a big bang (The Inflationary Universe). While Linde’s proposal is probably the best contemporary explanation of what caused the Big Bang, there is no verifiable evidence that a spontaneous quantum fluctuation did so. Th ...
The Cosmological Constant Problem, Dark Energy, and the
... just beyond current limits. Another frequently considered possibility is that General Relativity is modified at distances comparable to the size of the visible universe, so as to mimic a positive cosmological constant even though Λ = 0. In both cases, model parameters can be adjusted to lead to pre ...
... just beyond current limits. Another frequently considered possibility is that General Relativity is modified at distances comparable to the size of the visible universe, so as to mimic a positive cosmological constant even though Λ = 0. In both cases, model parameters can be adjusted to lead to pre ...
AS 4022: Cosmology - ASTRONOMY GROUP – University of St
... (Key players) • These structures and their movements – can't be explained purely by the expansion of the universe ...
... (Key players) • These structures and their movements – can't be explained purely by the expansion of the universe ...
cos1+2+3
... (Key players) • These structures and their movements – can't be explained purely by the expansion of the universe ...
... (Key players) • These structures and their movements – can't be explained purely by the expansion of the universe ...
(S. Lloyd 2001) - Digilander
... universe is close to its critical density. If the density of the universe is greater than the critical density, it will expand to a maximum size and then contract. If the density is less than or equal to the critical density, it will expand forever. The critical density can be estimated by a simple, ...
... universe is close to its critical density. If the density of the universe is greater than the critical density, it will expand to a maximum size and then contract. If the density is less than or equal to the critical density, it will expand forever. The critical density can be estimated by a simple, ...
Dark matter
... lightyears distant in one direction appears little different than a region 12 billion lightyears distant in the opposite direction. But since the universe is 'only' around 13.7 billion years old, it would appear these regions could never have been causally connected. How, then, can they be so simila ...
... lightyears distant in one direction appears little different than a region 12 billion lightyears distant in the opposite direction. But since the universe is 'only' around 13.7 billion years old, it would appear these regions could never have been causally connected. How, then, can they be so simila ...
Generation of Cosmological Perturbations by a First
... phase to a broken phase is of strongly first-order. However a very important issue of cosmology has been left out of arguments: One has to explain how and why the universe has attained the large scale inhomogeneities of matter distribution such as superclusters of galaxies. 9 ) This problem must be ...
... phase to a broken phase is of strongly first-order. However a very important issue of cosmology has been left out of arguments: One has to explain how and why the universe has attained the large scale inhomogeneities of matter distribution such as superclusters of galaxies. 9 ) This problem must be ...
The Origin of Matter-Antimatter Asymmetry Ning Bao Prashant Saraswat
... antimatter– spectra etc. all the same. Universe could consist of domains of matter and antimatter, with net baryon asymmetry. If matter/antimatter domains are in contact, gamma rays produced at boundary from annihilation Cosmic gamma ray background indicates domains must be at least ~Gpc in size ...
... antimatter– spectra etc. all the same. Universe could consist of domains of matter and antimatter, with net baryon asymmetry. If matter/antimatter domains are in contact, gamma rays produced at boundary from annihilation Cosmic gamma ray background indicates domains must be at least ~Gpc in size ...
PHY306 Introduction to Cosmology Practice Problems
... 8. Find the value of the radius of curvature, R0 , if Ωk0 = −0.09 (where Ωk0 = 1 − (Ωr0 + Ωm0 + ΩΛ0 )) and H0 = 50 km s−1 Mpc−1 . Hence determine the maximum proper distance r for which the difference between r and xk is less than 5% (for these values of Ωk and H0 ). (Note that Ωk and H0 are strongl ...
... 8. Find the value of the radius of curvature, R0 , if Ωk0 = −0.09 (where Ωk0 = 1 − (Ωr0 + Ωm0 + ΩΛ0 )) and H0 = 50 km s−1 Mpc−1 . Hence determine the maximum proper distance r for which the difference between r and xk is less than 5% (for these values of Ωk and H0 ). (Note that Ωk and H0 are strongl ...
Cosmo-PST
... 15. What observational evidence implies that most of the universe is dark matter? a. Large-scale gravitational fields are much stronger than can be accounted for by observed matter. b. Large-scale gravitational fields are much weaker than can be accounted for by observed matter. c. Small-scale gravi ...
... 15. What observational evidence implies that most of the universe is dark matter? a. Large-scale gravitational fields are much stronger than can be accounted for by observed matter. b. Large-scale gravitational fields are much weaker than can be accounted for by observed matter. c. Small-scale gravi ...
ASTROPHYSICS AND COSMOLOGY
... perfect gas of low-velocity cosmic strings [6]. In this paper, we study the model of a homogeneous and isotropic Universe with non-zero cosmological constant filled with a perfect gas of low-velocity cosmic strings. Throughout the paper, we will refer to this model as the ΛCS model. It is shown that ...
... perfect gas of low-velocity cosmic strings [6]. In this paper, we study the model of a homogeneous and isotropic Universe with non-zero cosmological constant filled with a perfect gas of low-velocity cosmic strings. Throughout the paper, we will refer to this model as the ΛCS model. It is shown that ...
How to create a universe - Philsci
... has a lepton counterpart called the Maki-Nakagawa-Sakata (MNS) matrix. This matrix also requires four parameters for its specification. ...
... has a lepton counterpart called the Maki-Nakagawa-Sakata (MNS) matrix. This matrix also requires four parameters for its specification. ...
Cosmic Microwave Background Anisotropies:
... Comments on Integrated Sachs-Wolfe Effect (ISW) • If the Universe is flat without dark energy (Einstein-de Sitter Univ.), potential stays constant for linear fluctuations: No ISW effect ISW probes curvature / dark energy •Curvature or dark energy can be only important in very late time for evolutio ...
... Comments on Integrated Sachs-Wolfe Effect (ISW) • If the Universe is flat without dark energy (Einstein-de Sitter Univ.), potential stays constant for linear fluctuations: No ISW effect ISW probes curvature / dark energy •Curvature or dark energy can be only important in very late time for evolutio ...
Early Universe Cosmology Advanced String School 2014 Puri, India
... the universe, this type of matter remains by far the least understood. There is one important omission in this list: scalar fields, which are often used in modelling the dynamics of the universe. We will treat these in detail later. We are finally ready to derive the Friedmann equations. These equat ...
... the universe, this type of matter remains by far the least understood. There is one important omission in this list: scalar fields, which are often used in modelling the dynamics of the universe. We will treat these in detail later. We are finally ready to derive the Friedmann equations. These equat ...
Ch. 23
... • Plank era: The earliest time in the universe (10-43 seconds) when all four forces—gravity, electromagnetism, the strong force, and the weak force—are thought to have been indistinguishable. GUT era: the next moment in time, when gravity was distinct from the other three forces, which together form ...
... • Plank era: The earliest time in the universe (10-43 seconds) when all four forces—gravity, electromagnetism, the strong force, and the weak force—are thought to have been indistinguishable. GUT era: the next moment in time, when gravity was distinct from the other three forces, which together form ...
Inflation (cosmology)
In physical cosmology, cosmic inflation, cosmological inflation, or just inflation is the exponential expansion of space in the early universe. The inflationary epoch lasted from 10−36 seconds after the Big Bang to sometime between 10−33 and 10−32 seconds. Following the inflationary period, the Universe continues to expand, but at a less rapid rate.The inflationary hypothesis was developed in the early 1980s. It explains the origin of the large-scale structure of the cosmos. Quantum fluctuations in the microscopic inflationary region, magnified to cosmic size, become the seeds for the growth of structure in the Universe (see galaxy formation and evolution and structure formation). Many physicists also believe that inflation explains why the Universe appears to be the same in all directions (isotropic), why the cosmic microwave background radiation is distributed evenly, why the Universe is flat, and why no magnetic monopoles have been observed.While the detailed particle physics mechanism responsible for inflation is not known, the basic picture makes a number of predictions that have been confirmed by observation. The hypothetical field thought to be responsible for inflation is called the inflaton.In 2002, three of the original architects of the theory were recognized for their major contributions; physicists Alan Guth of M.I.T., Andrei Linde of Stanford and Paul Steinhardt of Princeton shared the prestigious Dirac Prize ""for development of the concept of inflation in cosmology"".