Inflation - Caltech Astronomy
... universe respectively, G is the gravitational constant. The first of these two equations is the Einstein equation for a homogeneous universe containing a scalar field φ with energy density ρ = φ̇ 2 /2 + m2 φ 2 /2. The second equation is the standard Klein–Gordon equation for a homogeneous scalar fie ...
... universe respectively, G is the gravitational constant. The first of these two equations is the Einstein equation for a homogeneous universe containing a scalar field φ with energy density ρ = φ̇ 2 /2 + m2 φ 2 /2. The second equation is the standard Klein–Gordon equation for a homogeneous scalar fie ...
Search for Life in the Universe
... Universal Astrophysics (Part 1) • Universal laws of physics ultimately govern all processes • Homogenous expansion of the universe similar physical development everywhere: – Gravity Galaxies, stars, and planets – Nucleosynthesis abundances of elements ...
... Universal Astrophysics (Part 1) • Universal laws of physics ultimately govern all processes • Homogenous expansion of the universe similar physical development everywhere: – Gravity Galaxies, stars, and planets – Nucleosynthesis abundances of elements ...
2. Blackbody Radiation, Boltzmann Statistics, Temperature, and
... They are important because of the compact descriptions of systems that they give when Boltzmann statistics apply, either approximately or nearly exactly. Fortunately, this is most of the time in the Earth’s stratosphere and troposphere, and in other planetary atmospheres as long as the density is su ...
... They are important because of the compact descriptions of systems that they give when Boltzmann statistics apply, either approximately or nearly exactly. Fortunately, this is most of the time in the Earth’s stratosphere and troposphere, and in other planetary atmospheres as long as the density is su ...
(March 2004) (ppt-format) - RHIG
... simple relation of time = distance/speed. The Hubble Law can be rewritten 1/Ho = distance/speed. The Hubble constant tells you the age of the universe, i.e., how long the galaxies have been expanding away from each other: Age = 1/Ho. Age upper limit since the expansion has been slowing down due ...
... simple relation of time = distance/speed. The Hubble Law can be rewritten 1/Ho = distance/speed. The Hubble constant tells you the age of the universe, i.e., how long the galaxies have been expanding away from each other: Age = 1/Ho. Age upper limit since the expansion has been slowing down due ...
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... That is, not until Hogan realized that the Holographic Principle changes everything. If space-time is a grainy hologram, then you can think of the Universe as a sphere whose outer surface is papered in Planck length-sized squares, each containing one bit of information. The Holographic Principle say ...
... That is, not until Hogan realized that the Holographic Principle changes everything. If space-time is a grainy hologram, then you can think of the Universe as a sphere whose outer surface is papered in Planck length-sized squares, each containing one bit of information. The Holographic Principle say ...
a MS Word version.
... 18. Describe the main "standard candles" that are used to measure the distances to galaxies that are used to determine the Hubble redshift relation. What is the approximate current best value for Hubble's constant? Given this constant, how is the Hubble relation used to determine the distance to far ...
... 18. Describe the main "standard candles" that are used to measure the distances to galaxies that are used to determine the Hubble redshift relation. What is the approximate current best value for Hubble's constant? Given this constant, how is the Hubble relation used to determine the distance to far ...
Signatures of the first stars in the 21cm Emission and Absorption
... has yet reached. – For CDMΛ model: first stars form at z ~ 40 from 6sigma fluctuations. ...
... has yet reached. – For CDMΛ model: first stars form at z ~ 40 from 6sigma fluctuations. ...
Cosmic Rays and Climate
... Understanding the cosmic ray climate link could have large implications in our understanding of climate changes and possible evolution on Earth. The evolution of the Milky Way and the Earth is linked ...
... Understanding the cosmic ray climate link could have large implications in our understanding of climate changes and possible evolution on Earth. The evolution of the Milky Way and the Earth is linked ...
dark - The Institute of Mathematical Sciences
... times larger), stars collect themselves into galaxies. Our Sun is an average star in an average galaxy called the Milky Way. The Milky Way contains about 100 billion stars. Yes, that's 100,000,000,000 stars! On still larger scales, individual galaxies are concentrated into groups, or what astronomer ...
... times larger), stars collect themselves into galaxies. Our Sun is an average star in an average galaxy called the Milky Way. The Milky Way contains about 100 billion stars. Yes, that's 100,000,000,000 stars! On still larger scales, individual galaxies are concentrated into groups, or what astronomer ...
Hubble - schoolphysics
... The Hubble formula provides a very powerful way of determining not only distances of remote galaxies but also the age of the Universe itself. He stated that they were related by the formula: Velocity of recession (v) = Hubble constant (H) x distance (r) where H is Hubble's constant and r is the dist ...
... The Hubble formula provides a very powerful way of determining not only distances of remote galaxies but also the age of the Universe itself. He stated that they were related by the formula: Velocity of recession (v) = Hubble constant (H) x distance (r) where H is Hubble's constant and r is the dist ...
in the Universe
... The rotation velocity is found not to decrease with increasing distance from the galactic center This implies that the galaxy's cumulative mass must continue to increase with the radial distance from the center of the galaxy, even though the light levels off ...
... The rotation velocity is found not to decrease with increasing distance from the galactic center This implies that the galaxy's cumulative mass must continue to increase with the radial distance from the center of the galaxy, even though the light levels off ...
2. The World at Large: From the Big Bang to Black Holes
... If the stars were distributed uniformly in space, were shining forever without change, then there would be no gap between the stars. In every direction you would see a star – some close, some far away. The night sky would be everywhere as bright as the surface of a star. The night sky is dark, howev ...
... If the stars were distributed uniformly in space, were shining forever without change, then there would be no gap between the stars. In every direction you would see a star – some close, some far away. The night sky would be everywhere as bright as the surface of a star. The night sky is dark, howev ...
uncertainties from CROSS SECTIONS
... The case for antiprotons Antiprotons are produced in the Galaxy by fragmentation of proton and He (and marginally heavier nuclei) on the ISM (secondary antiprotons). These antiprotons would be the background to an exotic component due to ...
... The case for antiprotons Antiprotons are produced in the Galaxy by fragmentation of proton and He (and marginally heavier nuclei) on the ISM (secondary antiprotons). These antiprotons would be the background to an exotic component due to ...
Spiralicity and Motion on Cosmic Scale
... General relativity has recently been confirmed on the nearby universe [4]. The predicted gravitational redshift of relativity has been found from the astronomical findings on galactic clusters, where groups of thousands galaxies are held together by their own gravity field to bend the light and to c ...
... General relativity has recently been confirmed on the nearby universe [4]. The predicted gravitational redshift of relativity has been found from the astronomical findings on galactic clusters, where groups of thousands galaxies are held together by their own gravity field to bend the light and to c ...
Document
... making neutrinos the second most abundant particles in the Universe. Because these relic neutrinos have a predicted temperature of about 1.95 Kelvin, they are extremely difficult to detect in the laboratory. Nonetheless, it is possible to verify the existence of cosmic neutrinos indirectly via their ...
... making neutrinos the second most abundant particles in the Universe. Because these relic neutrinos have a predicted temperature of about 1.95 Kelvin, they are extremely difficult to detect in the laboratory. Nonetheless, it is possible to verify the existence of cosmic neutrinos indirectly via their ...
OSTP_Brief_AdLIGO_1204
... Using simulations an upper limit on the associated gravitational wave strength at the detector at the level of hRSS~6x10-20 Hz-1/2 was set Radiation from a broadband burst at this distance? EGW > 105M8 ...
... Using simulations an upper limit on the associated gravitational wave strength at the detector at the level of hRSS~6x10-20 Hz-1/2 was set Radiation from a broadband burst at this distance? EGW > 105M8 ...
Dark Energy: back to Newton?
... It has become apparent that the Earth, the planets, the stars and everything we are familiar with make up only a tiny 4% of the total matter and energy in the universe. Increasingly dependable evidence from gravitational lensing, galaxy rotation curves and studies of the cosmic microwave background ...
... It has become apparent that the Earth, the planets, the stars and everything we are familiar with make up only a tiny 4% of the total matter and energy in the universe. Increasingly dependable evidence from gravitational lensing, galaxy rotation curves and studies of the cosmic microwave background ...
class 2, S11
... —No, the observable portion of the universe is about 14 billion light-years in radius because the universe is about 14 billion years old. ALSO (not in Ch. 1 of the book), we can “see” only about 4% of the universe, 96% is made of “dark matter” and “dark energy”. ...
... —No, the observable portion of the universe is about 14 billion light-years in radius because the universe is about 14 billion years old. ALSO (not in Ch. 1 of the book), we can “see” only about 4% of the universe, 96% is made of “dark matter” and “dark energy”. ...
PHY306 Introduction to Cosmology Practice Problems
... (b) Find, in terms of Ωm0 and ΩΛ0 , the value of a at which the expansion of a universe with non-zero Λ begins to accelerate. Explain why your result does not depend on the curvature Ωk0 . (c) Explain why, in spite of the above, a closed universe with non-zero Λ may recollapse, if Λ is small enough. ...
... (b) Find, in terms of Ωm0 and ΩΛ0 , the value of a at which the expansion of a universe with non-zero Λ begins to accelerate. Explain why your result does not depend on the curvature Ωk0 . (c) Explain why, in spite of the above, a closed universe with non-zero Λ may recollapse, if Λ is small enough. ...
Record: 1 Will dark energy TEAR the universe apart? Page 1 of 8
... value more negative than - /3. The value also determines how fast the universe expands. And there's more: The equation of state value does not need to remain constant; it can vary in time. Cosmologists split the dark energy candidates by their equation of state values. Quintessence has a value betwe ...
... value more negative than - /3. The value also determines how fast the universe expands. And there's more: The equation of state value does not need to remain constant; it can vary in time. Cosmologists split the dark energy candidates by their equation of state values. Quintessence has a value betwe ...
The Evolution of the Universe - Western Washington University
... in the first place. In fact, the closer we look to time "zero," the less certain we are about what actually happened, because our current description of physical laws do not yet apply to such extremes of nature. The Big Bang scenario simply assumes that space, time, and energy already existed. But i ...
... in the first place. In fact, the closer we look to time "zero," the less certain we are about what actually happened, because our current description of physical laws do not yet apply to such extremes of nature. The Big Bang scenario simply assumes that space, time, and energy already existed. But i ...
The relationship between difference and ratio and a proposal
... as an energy density, yet manifests itself in the abundance of de facto not reversed ‘directed’ motion, hence, is a measure for kinetic energy density of the irreversible. Time only exists if there is change, most generally, change in the state of the object(s) in question; objects being particles o ...
... as an energy density, yet manifests itself in the abundance of de facto not reversed ‘directed’ motion, hence, is a measure for kinetic energy density of the irreversible. Time only exists if there is change, most generally, change in the state of the object(s) in question; objects being particles o ...
Cosmic microwave background
The cosmic microwave background (CMB) is the thermal radiation left over from the time of recombination in Big Bang cosmology. In older literature, the CMB is also variously known as cosmic microwave background radiation (CMBR) or ""relic radiation."" The CMB is a cosmic background radiation that is fundamental to observational cosmology because it is the oldest light in the universe, dating to the epoch of recombination. With a traditional optical telescope, the space between stars and galaxies (the background) is completely dark. However, a sufficiently sensitive radio telescope shows a faint background glow, almost exactly the same in all directions, that is not associated with any star, galaxy, or other object. This glow is strongest in the microwave region of the radio spectrum. The accidental discovery of CMB in 1964 by American radio astronomers Arno Penzias and Robert Wilson was the culmination of work initiated in the 1940s, and earned the discoverers the 1978 Nobel Prize.The CMB is a snapshot of the oldest light in our Universe, imprinted on the sky when the Universe was just 380,000 years old. It shows tiny temperature fluctuations that correspond to regions of slightly different densities, representing the seeds of all future structure: the stars and galaxies of today.The CMB is well explained as radiation left over from an early stage in the development of the universe, and its discovery is considered a landmark test of the Big Bang model of the universe. When the universe was young, before the formation of stars and planets, it was denser, much hotter, and filled with a uniform glow from a white-hot fog of hydrogen plasma. As the universe expanded, both the plasma and the radiation filling it grew cooler. When the universe cooled enough, protons and electrons combined to form neutral atoms. These atoms could no longer absorb the thermal radiation, and so the universe became transparent instead of being an opaque fog. Cosmologists refer to the time period when neutral atoms first formed as the recombination epoch, and the event shortly afterwards when photons started to travel freely through space rather than constantly being scattered by electrons and protons in plasma is referred to as photon decoupling. The photons that existed at the time of photon decoupling have been propagating ever since, though growing fainter and less energetic, since the expansion of space causes their wavelength to increase over time (and wavelength is inversely proportional to energy according to Planck's relation). This is the source of the alternative term relic radiation. The surface of last scattering refers to the set of points in space at the right distance from us so that we are now receiving photons originally emitted from those points at the time of photon decoupling.Precise measurements of the CMB are critical to cosmology, since any proposed model of the universe must explain this radiation. The CMB has a thermal black body spectrum at a temperature of 7000272548000000000♠2.72548±0.00057 K. The spectral radiance dEν/dν peaks at 160.2 GHz, in the microwave range of frequencies. (Alternatively if spectral radiance is defined as dEλ/dλ then the peak wavelength is 1.063 mm.) The glow is very nearly uniform in all directions, but the tiny residual variations show a very specific pattern, the same as that expected of a fairly uniformly distributed hot gas that has expanded to the current size of the universe. In particular, the spectral radiance at different angles of observation in the sky contains small anisotropies, or irregularities, which vary with the size of the region examined. They have been measured in detail, and match what would be expected if small thermal variations, generated by quantum fluctuations of matter in a very tiny space, had expanded to the size of the observable universe we see today. This is a very active field of study, with scientists seeking both better data (for example, the Planck spacecraft) and better interpretations of the initial conditions of expansion. Although many different processes might produce the general form of a black body spectrum, no model other than the Big Bang has yet explained the fluctuations. As a result, most cosmologists consider the Big Bang model of the universe to be the best explanation for the CMB.The high degree of uniformity throughout the observable universe and its faint but measured anisotropy lend strong support for the Big Bang model in general and the ΛCDM (""Lambda Cold Dark Matter"") model in particular. Moreover, the fluctuations are coherent on angular scales that are larger than the apparent cosmological horizon at recombination. Either such coherence is acausally fine-tuned, or cosmic inflation occurred.