Dark matter, neutron stars and strange quark matter
... result of multiple WIMP annihilations over scales of several fm (typical size of a strangelet). A long-lived cluster may be formed from different small clusters with interdistance l on the diffusion time-scale, tdiff ∼ l/vdiff , before they decay over a mean lifetime, τ ∼ 10−10 − 10−5 s. This effect ...
... result of multiple WIMP annihilations over scales of several fm (typical size of a strangelet). A long-lived cluster may be formed from different small clusters with interdistance l on the diffusion time-scale, tdiff ∼ l/vdiff , before they decay over a mean lifetime, τ ∼ 10−10 − 10−5 s. This effect ...
Galaxy Hunters Article, Cosmology Information, First Star Facts
... clouds. As the gases cooled, they coalesced at the center of each cloud into a clump no larger than our sun. The dump collapsed further, while surrounding gas piled on top of it. In this way it grew into a behemoth about 100 times the mass of the sun. Finally, several million years after the entire ...
... clouds. As the gases cooled, they coalesced at the center of each cloud into a clump no larger than our sun. The dump collapsed further, while surrounding gas piled on top of it. In this way it grew into a behemoth about 100 times the mass of the sun. Finally, several million years after the entire ...
The Cosmic Microwave Background
... call these fluctuations primary anisotropies, while a secondary anisotropies can also be generated between recombination and the present. ...
... call these fluctuations primary anisotropies, while a secondary anisotropies can also be generated between recombination and the present. ...
Paper - Astrophysics - University of Oxford
... 2.1. Formation of stars across the Universe When did stars form? To answer this basic question we can make use of the fact that every star must eventually die. Indeed the more massive stars die in spectacular supernova explosions that can outshine a whole galaxy. With an ELT these explosions can be ...
... 2.1. Formation of stars across the Universe When did stars form? To answer this basic question we can make use of the fact that every star must eventually die. Indeed the more massive stars die in spectacular supernova explosions that can outshine a whole galaxy. With an ELT these explosions can be ...
Hoffmann_Photon_Science_Novosibirsk_1__2015
... As a result a new neutral and very light particle is predicted, the Axion (Weinberg, Wilczeck) Couples with two photons via Primakoff Effect in any model Very weak interaction probability with matter Spinless boson ...
... As a result a new neutral and very light particle is predicted, the Axion (Weinberg, Wilczeck) Couples with two photons via Primakoff Effect in any model Very weak interaction probability with matter Spinless boson ...
MOND
... Our current understanding of the Universe though rests on some important assumptions and one of them is that luminous matter (i.e. baryons) contributes only a small fraction of the mean density in the Universe, the bulk being made up of some combination of vacuum energy and dark matter (cf. Spergel ...
... Our current understanding of the Universe though rests on some important assumptions and one of them is that luminous matter (i.e. baryons) contributes only a small fraction of the mean density in the Universe, the bulk being made up of some combination of vacuum energy and dark matter (cf. Spergel ...
The 6dF Galaxy Survey: Mass and Motions in the Local Universe
... uniformity with which targets are observed, depend critically on the tiling of the sky with fields. High completeness and uniformity are achieved by covering the sky twice over with approximately 1500 6◦ fields, using a Metropolis algorithm to optimize the placement of the fields (Campbell et al. 20 ...
... uniformity with which targets are observed, depend critically on the tiling of the sky with fields. High completeness and uniformity are achieved by covering the sky twice over with approximately 1500 6◦ fields, using a Metropolis algorithm to optimize the placement of the fields (Campbell et al. 20 ...
Slides
... – If supersymmetry is correct, they would also have new, but much more massive relatives called superpartners Theoretically this is very nice – eliminates mathematical problems in standard model – allows unification of forces at much higher energies – provides a path to the incorporation of gravity ...
... – If supersymmetry is correct, they would also have new, but much more massive relatives called superpartners Theoretically this is very nice – eliminates mathematical problems in standard model – allows unification of forces at much higher energies – provides a path to the incorporation of gravity ...
Slide 1
... • One of our favorite reasons is to look at the atomic hydrogen clouds in the Milky Way. • The clouds lay very far out from the galactic center (further out than our sun) and are rotating faster than they should be if they were just feeling the gravity of the mass we can “see” Big Bang, Black Early ...
... • One of our favorite reasons is to look at the atomic hydrogen clouds in the Milky Way. • The clouds lay very far out from the galactic center (further out than our sun) and are rotating faster than they should be if they were just feeling the gravity of the mass we can “see” Big Bang, Black Early ...
Summarising Constraints On Dark Matter At The Large Hadron
... results analysed and discussed. Lastly, a brief outlook on future work is given. ...
... results analysed and discussed. Lastly, a brief outlook on future work is given. ...
Galaxies Galaxies M81
... • Beginning of the 20th century, what we now call galaxies were referred to as “spiral nebulae” • Believed to be clouds of gas and stars associated with Milky Way. • In 1924 Edwin Hubble measured distance to the “Great Nebula in Andromeda” (M 31) and found its distance to be much larger than the dia ...
... • Beginning of the 20th century, what we now call galaxies were referred to as “spiral nebulae” • Believed to be clouds of gas and stars associated with Milky Way. • In 1924 Edwin Hubble measured distance to the “Great Nebula in Andromeda” (M 31) and found its distance to be much larger than the dia ...
Dark matter
Dark matter is a hypothetical kind of matter that cannot be seen with telescopes but would account for most of the matter in the universe. The existence and properties of dark matter are inferred from its gravitational effects on visible matter, on radiation, and on the large-scale structure of the universe. Dark matter has not been detected directly, making it one of the greatest mysteries in modern astrophysics.Dark matter neither emits nor absorbs light or any other electromagnetic radiation at any significant level. According to the Planck mission team, and based on the standard model of cosmology, the total mass–energy of the known universe contains 4.9% ordinary matter, 26.8% dark matter and 68.3% dark energy. Thus, dark matter is estimated to constitute 84.5% of the total matter in the universe, while dark energy plus dark matter constitute 95.1% of the total mass–energy content of the universe.Astrophysicists hypothesized the existence of dark matter to account for discrepancies between the mass of large astronomical objects determined from their gravitational effects, and their mass as calculated from the observable matter (stars, gas, and dust) that they can be seen to contain. Their gravitational effects suggest that their masses are much greater than the observable matter survey suggests. Dark matter was postulated by Jan Oort in 1932, albeit based upon insufficient evidence, to account for the orbital velocities of stars in the Milky Way. In 1933, Fritz Zwicky was the first to use the virial theorem to infer the existence of unseen matter, which he referred to as dunkle Materie 'dark matter'. More robust evidence from galaxy rotation curves was discovered by Horace W. Babcock in 1939, but was not attributed to dark matter. The first hypothesis to postulate ""dark matter"" based upon robust evidence was formulated by Vera Rubin and Kent Ford in the 1960s–1970s, using galaxy rotation curves. Subsequently, many other observations have indicated the presence of dark matter in the universe, including gravitational lensing of background objects by galaxy clusters such as the Bullet Cluster, the temperature distribution of hot gas in galaxies and clusters of galaxies and, more recently, the pattern of anisotropies in the cosmic microwave background. According to consensus among cosmologists, dark matter is composed primarily of a not yet characterized type of subatomic particle.The search for this particle, by a variety of means, is one of the major efforts in particle physics today.Although the existence of dark matter is generally accepted by the mainstream scientific community, some alternative theories of gravity have been proposed, such as MOND and TeVeS, which try to account for the anomalous observations without requiring additional matter. However, these theories cannot account for the properties of galaxy clusters.