FINAL PROGRAM - Drifting through the Cosmic Web
... (Poster) Weak Lensing Signatures of the Connexion between Massive Dark Matter Halos and the Cosmic Web ...
... (Poster) Weak Lensing Signatures of the Connexion between Massive Dark Matter Halos and the Cosmic Web ...
Full text in PDF form
... section that turns out to be proportional to the mass m and the age of the Universe t. This gives a Machian approach to entropy. The gravitational size related to this gravitational cross section expands as the Universe does. This entropy has an extensive property and increases linearly with time. I ...
... section that turns out to be proportional to the mass m and the age of the Universe t. This gives a Machian approach to entropy. The gravitational size related to this gravitational cross section expands as the Universe does. This entropy has an extensive property and increases linearly with time. I ...
Into the darkness peering
... Can be well modeled X-rays are optically thin thermal radiation from material nearly in collisional equilibrium Not as simple as the microwave background Simpler than supernovae, galaxies or AGN Fewer projection effects with X-ray selection X-rays are more peaked than galaxy distribution Fewer foreg ...
... Can be well modeled X-rays are optically thin thermal radiation from material nearly in collisional equilibrium Not as simple as the microwave background Simpler than supernovae, galaxies or AGN Fewer projection effects with X-ray selection X-rays are more peaked than galaxy distribution Fewer foreg ...
The Square Kilometre Array Fact sheet for journalists
... seen with an optical telescope and can reveal areas of space that may be obscured with cosmic dust. Signals received by the SKA will be transferred to a central high performance super computer by optical fibres. The rate at which the vast quantities of data will be transferred to the supercomputer w ...
... seen with an optical telescope and can reveal areas of space that may be obscured with cosmic dust. Signals received by the SKA will be transferred to a central high performance super computer by optical fibres. The rate at which the vast quantities of data will be transferred to the supercomputer w ...
Let`s discuss some problems of Physics and Astronomy
... The proof: the satellite, moving round Earth will fly along the tangent to its orbit if the gravitational forces were turned off. In order to keep its movement along the orbit the satellite has to have a jet which would reconstruct the force equal to former gravitational with value and direction. An ...
... The proof: the satellite, moving round Earth will fly along the tangent to its orbit if the gravitational forces were turned off. In order to keep its movement along the orbit the satellite has to have a jet which would reconstruct the force equal to former gravitational with value and direction. An ...
APS Slide Presentation
... holes, and inflation have only begun to impact physics in general and cosmology in particular. Dark energy generally has not been factored into all universe formation models, but when considered, it changes everything. The function of dark energy is to push the universe apart, separating each super ...
... holes, and inflation have only begun to impact physics in general and cosmology in particular. Dark energy generally has not been factored into all universe formation models, but when considered, it changes everything. The function of dark energy is to push the universe apart, separating each super ...
Advanced Topics in Cosmology: A Pedagogical Introduction
... The variables Ωi ≡ ρi /ρc will give the fractional contribution of different components of the universe (i denoting 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 deter ...
... The variables Ωi ≡ ρi /ρc will give the fractional contribution of different components of the universe (i denoting 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 deter ...
Response to Dr. Laurence Krauss of the
... expansion. Krauss needs the universe to expand because he insists on using Einstein’s general relativity to explain the universe. One of the best geocentric explanations is that the redshift is caused by the centrifugal force on light in a rotating and yet non-expanding universe. Second, it is not t ...
... expansion. Krauss needs the universe to expand because he insists on using Einstein’s general relativity to explain the universe. One of the best geocentric explanations is that the redshift is caused by the centrifugal force on light in a rotating and yet non-expanding universe. Second, it is not t ...
The Fate of Inflaton Fluctuations in Multi
... believed to be the origin of the large scale structure in the Universe [1]. Understanding them is an important aspect of early Universe cosmology. Flat directions are directions in field space where the potential is constant. In this situation, the field can vary at no cost in energy and may acquir ...
... believed to be the origin of the large scale structure in the Universe [1]. Understanding them is an important aspect of early Universe cosmology. Flat directions are directions in field space where the potential is constant. In this situation, the field can vary at no cost in energy and may acquir ...
The Formation of Primordial Luminous Objects - SLAC
... This kind of spectrum, in which fluctuations are typically larger on small scales, leads naturally to hierarchical structure formation, since smallscale fluctuations are the first to become non-linear (i.e. to reach δ ∼ 1), collapse and form some kind of astronomical object. It is also worth remarki ...
... This kind of spectrum, in which fluctuations are typically larger on small scales, leads naturally to hierarchical structure formation, since smallscale fluctuations are the first to become non-linear (i.e. to reach δ ∼ 1), collapse and form some kind of astronomical object. It is also worth remarki ...
threshold 1— the big bang
... • Ptolemy’s Universe consisted of six planets, the Moon, and the Sun that moved in circular orbits around the Earth. • Over time, human observations of the planets and stars became more precise and led some scientists to suggest alternative theories. • Copernicus, Kepler, and Galileo contributed to ...
... • Ptolemy’s Universe consisted of six planets, the Moon, and the Sun that moved in circular orbits around the Earth. • Over time, human observations of the planets and stars became more precise and led some scientists to suggest alternative theories. • Copernicus, Kepler, and Galileo contributed to ...
Breaks in gamma-ray spectra of distant blazars and transparency of
... absorption. Since the bulk of the data they used correspond to the energies for which the opacity is low, this effect was seen in stacked samples only. This result does not contradict to ours because it does not exclude the opacity below the lowest model and even favours it for high energies, cf. Fi ...
... absorption. Since the bulk of the data they used correspond to the energies for which the opacity is low, this effect was seen in stacked samples only. This result does not contradict to ours because it does not exclude the opacity below the lowest model and even favours it for high energies, cf. Fi ...
General Astronomy Dark Matter
... • The odds of a MACHO moving precisely enough in front of a given star in the LMC is tiny - but if you look at enough stars, it will happen regularly. • The Great Melbourne Telescope at Mt Stromlo was used for the MACHO project - monitoring 16 million stars in the LMC every clear night for five year ...
... • The odds of a MACHO moving precisely enough in front of a given star in the LMC is tiny - but if you look at enough stars, it will happen regularly. • The Great Melbourne Telescope at Mt Stromlo was used for the MACHO project - monitoring 16 million stars in the LMC every clear night for five year ...
Photon-Graviton Recycling as Cause of Gravitation
... and photon energy are everywhere being interconverted at fractional rates proportional to the Hubble constant H0. Evidence for the postulated graviton decay was suggested to lie in observable planetary heating and expansion. The greatest quantity of gravitational potential energy associated with a m ...
... and photon energy are everywhere being interconverted at fractional rates proportional to the Hubble constant H0. Evidence for the postulated graviton decay was suggested to lie in observable planetary heating and expansion. The greatest quantity of gravitational potential energy associated with a m ...
Cosmic Order out of Primordial Chaos Jones, Bernard JT
... A general density fluctuation field for a component of the universe with respect to its cosmic background mass density ρu is defined by δ(r, t) = ...
... A general density fluctuation field for a component of the universe with respect to its cosmic background mass density ρu is defined by δ(r, t) = ...
Cosmic Hide and Seek: the Search for the Missing
... the farther the light is shifted. But the Doppler shift for light is very subtle and cannot be detected with the naked eye. Scientists use a device called a spectroscope to measure Doppler Shift and determine how fast stars and galaxies are moving (7). Rotational Velocity. Using the power of the Do ...
... the farther the light is shifted. But the Doppler shift for light is very subtle and cannot be detected with the naked eye. Scientists use a device called a spectroscope to measure Doppler Shift and determine how fast stars and galaxies are moving (7). Rotational Velocity. Using the power of the Do ...
Chapter 31
... within the dotted box would not contain 3 galaxies after a time. The steady-state theory requires new matter to be added so that the area within the dotted box always contains 3 galaxies. ...
... within the dotted box would not contain 3 galaxies after a time. The steady-state theory requires new matter to be added so that the area within the dotted box always contains 3 galaxies. ...
Signals from the Beginnings of the World - Max-Planck
... of a cosmic mass swallower: a black hole is born. Astrophysicists are working on the theoretical details of this scenario. What causes gas to stream into a central compact object at high velocity and thus convert its surroundings into a source of high-energy light and plasma jets? If you want to und ...
... of a cosmic mass swallower: a black hole is born. Astrophysicists are working on the theoretical details of this scenario. What causes gas to stream into a central compact object at high velocity and thus convert its surroundings into a source of high-energy light and plasma jets? If you want to und ...
doc - StealthSkater
... 2. A much stronger assumption is that the star eventually rotates with the same velocity as the distant stars of Milky Way around its center after the ripping out. If the dark matter is also rotating as it should be and forms a halo, the gravitational interactions with it could force the hydrodynami ...
... 2. A much stronger assumption is that the star eventually rotates with the same velocity as the distant stars of Milky Way around its center after the ripping out. If the dark matter is also rotating as it should be and forms a halo, the gravitational interactions with it could force the hydrodynami ...
Generation of Cosmological Perturbations by a First
... As the time proceeds, BWHs evaporate and OH changes into Or. It can be shown that an appreciable portion of Or thus produced is in the growing mode (Orcxt). Details on this point will be given elsewhere. 16) Now, assuming a sufficient number of baryons are present and their distribution is homogeneo ...
... As the time proceeds, BWHs evaporate and OH changes into Or. It can be shown that an appreciable portion of Or thus produced is in the growing mode (Orcxt). Details on this point will be given elsewhere. 16) Now, assuming a sufficient number of baryons are present and their distribution is homogeneo ...
Big Bang Nucleosynthesis - Chalmers
... The fundamental physical processes that govern the Big Bang nucleosynthesis (BBN) have been studied. BBN refers to the production of predominantly light nuclei in the early Universe, which occurs on the time scale of a few minutes after the bang. An initial intensive literature study was carried out ...
... The fundamental physical processes that govern the Big Bang nucleosynthesis (BBN) have been studied. BBN refers to the production of predominantly light nuclei in the early Universe, which occurs on the time scale of a few minutes after the bang. An initial intensive literature study was carried out ...
Astro 3303 - Cornell Astronomy
... Evidence for the Big Bang Model • Olber’s paradox: (Heinrich Olbers: 1823) • The sky is dark at night. • Hubble’s Law & the expansion of the Universe (Edwin Hubble: 1927) • If the universe is finite in space and time and is expanding, it must have been smaller in the past. • The Cosmic Microwave Ba ...
... Evidence for the Big Bang Model • Olber’s paradox: (Heinrich Olbers: 1823) • The sky is dark at night. • Hubble’s Law & the expansion of the Universe (Edwin Hubble: 1927) • If the universe is finite in space and time and is expanding, it must have been smaller in the past. • The Cosmic Microwave Ba ...
AST 207 Final Exam 14 December 2009
... c. (1 pts.) What will the sun become when it completely exhausts its fuel? (1 pt.) How big will it be? (1 pt.) What will prevent gravity from making it collapse? d. (2 pts.) The sun is losing more mass than can be accounted with the loss of protons, neutrons, and electrons. Explain how that is possi ...
... c. (1 pts.) What will the sun become when it completely exhausts its fuel? (1 pt.) How big will it be? (1 pt.) What will prevent gravity from making it collapse? d. (2 pts.) The sun is losing more mass than can be accounted with the loss of protons, neutrons, and electrons. Explain how that is possi ...
Week 2
... absorption coefficient has the much higher value of αν ≈ 1400 cm−1 . The absorption efficient can be either positive or negative in sign. If αν > 0, then energy is removed from the beam of light as it travels. if αν < 0, then energy is added to the beam by stimulated emission (as opposed to the spon ...
... absorption coefficient has the much higher value of αν ≈ 1400 cm−1 . The absorption efficient can be either positive or negative in sign. If αν > 0, then energy is removed from the beam of light as it travels. if αν < 0, then energy is added to the beam by stimulated emission (as opposed to the spon ...
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.