Phase Transitions of the First Kind as Radiation
... However, it is apparently tantamount to an implicit assumption that the removal of latent heat (bond energy) at transition into more condensed phases should occur via heat conductivity, even at constant temperature in the condition of supersaturation, etc. So, possible ways of the removal of latent ...
... However, it is apparently tantamount to an implicit assumption that the removal of latent heat (bond energy) at transition into more condensed phases should occur via heat conductivity, even at constant temperature in the condition of supersaturation, etc. So, possible ways of the removal of latent ...
of satellite data, and associated opportunities for the LHC
... poorly so soft antiprotons get to detector • present in old data, so old data was background + “signal” • old data fitted as if just background, result used as background in recent analyses Gammas? Fermi/Glast data ? Synchrotron radiation – OK for some magnetic field parameters ...
... poorly so soft antiprotons get to detector • present in old data, so old data was background + “signal” • old data fitted as if just background, result used as background in recent analyses Gammas? Fermi/Glast data ? Synchrotron radiation – OK for some magnetic field parameters ...
SPECTROSCOPY OF HIGH-REDSHIFT TYPE Ia SUPERNOVAE
... orthogonal direction to the flat universe line, and towards higher values of both Ω M and ΩΛ . This can readily be understood via a simple analogy: the matter term in the Friedmann equations acts like a “break” on the expansion, whereas the Λ term acts like an “accelerator”. One can imagine obtainin ...
... orthogonal direction to the flat universe line, and towards higher values of both Ω M and ΩΛ . This can readily be understood via a simple analogy: the matter term in the Friedmann equations acts like a “break” on the expansion, whereas the Λ term acts like an “accelerator”. One can imagine obtainin ...
PDF only - at www.arxiv.org.
... more strongly polarized ones, tend to have their plane of integrated radio polarization, corrected for Faraday rotation, usually perpendicular and occasionally parallel to the radio source axis,18 to put a limit of 6◦ at the 95% confidence level (CL) to any rotation of the plane of polarization for ...
... more strongly polarized ones, tend to have their plane of integrated radio polarization, corrected for Faraday rotation, usually perpendicular and occasionally parallel to the radio source axis,18 to put a limit of 6◦ at the 95% confidence level (CL) to any rotation of the plane of polarization for ...
Chapter 14 Cosmology II
... system. For example, two distant galaxies are considered to be separated by a constant distance when measured in units of coordinate length . The coordinate grid used by the spacetime transformational model has similarities to the coordinate grid used by the Λ‐CDM model. Both gri ...
... system. For example, two distant galaxies are considered to be separated by a constant distance when measured in units of coordinate length . The coordinate grid used by the spacetime transformational model has similarities to the coordinate grid used by the Λ‐CDM model. Both gri ...
22. Dark Matter and the Fate of the Universe
... • What are WIMPs, and can they account for dark matter? • WIMP is short for weakly interacting massive particle, and refers to undiscovered particles of extraordinary (nonbaryonic) matter that do not interact with light (instead interacting only through the weak force and gravity). WIMPs are the lea ...
... • What are WIMPs, and can they account for dark matter? • WIMP is short for weakly interacting massive particle, and refers to undiscovered particles of extraordinary (nonbaryonic) matter that do not interact with light (instead interacting only through the weak force and gravity). WIMPs are the lea ...
Lecture 3: Emission and absorption
... where Sν = jν /αν is the source function. Since the gas is in thermal equilibrium with the radiation, then we take this source function to be the Planck function, and assume T is constant: ...
... where Sν = jν /αν is the source function. Since the gas is in thermal equilibrium with the radiation, then we take this source function to be the Planck function, and assume T is constant: ...
Slides - Indico
... -We are in the “Precision Era” of Cosmology. BBN parameters, such as Wb, Yp, (D/H)p are known with high (and increasing) precision. Uncertainties of calculations are often limited by the poor knowledge of the cross section of few reaction, at BBN energies. -Accurate measurements at low energy must b ...
... -We are in the “Precision Era” of Cosmology. BBN parameters, such as Wb, Yp, (D/H)p are known with high (and increasing) precision. Uncertainties of calculations are often limited by the poor knowledge of the cross section of few reaction, at BBN energies. -Accurate measurements at low energy must b ...
A self-consistent and time-dependent hybrid blazar emission model
... able to exploit outbursts of blazars and the timing signatures in different energy bands to narrow down the parameters used in the modelling process and distinguish between leptonic and hadronic dominated jets. In the next section we give a description of our model and its principle properties and a ...
... able to exploit outbursts of blazars and the timing signatures in different energy bands to narrow down the parameters used in the modelling process and distinguish between leptonic and hadronic dominated jets. In the next section we give a description of our model and its principle properties and a ...
Natasha Wood
... Mentors: Marco Ajello & Masaaki Hayashida How will you be doing the comparisons? An active galactic nucleus (AGN) is a relatively small region of space at the center of a galaxy that is very luminous over all or part of the electromagnetic spectrum1. This radiation is theorized to be a product of ma ...
... Mentors: Marco Ajello & Masaaki Hayashida How will you be doing the comparisons? An active galactic nucleus (AGN) is a relatively small region of space at the center of a galaxy that is very luminous over all or part of the electromagnetic spectrum1. This radiation is theorized to be a product of ma ...
Predicting the CIB-φ contamination in the cross
... combinations that reconstruct the tSZ Compton parameter from Planck frequency maps. We conclude that even in an optimistic case, the CIB-φ contamination is significant with respect to the tSZ-φ signal itself. Consequently, we stress that tSZ-φ analyses that are based on Compton parameter maps are hi ...
... combinations that reconstruct the tSZ Compton parameter from Planck frequency maps. We conclude that even in an optimistic case, the CIB-φ contamination is significant with respect to the tSZ-φ signal itself. Consequently, we stress that tSZ-φ analyses that are based on Compton parameter maps are hi ...
Correlation of the highest-energy cosmic rays with the positions of
... The identification of the sources of the cosmic rays with the highest-energies so far detected has been a great challenge ever since the first event with energy around 1020 eV was reported [2]. If the highest-energy cosmic rays are predominantly protons and nuclei, only sources which are less than abo ...
... The identification of the sources of the cosmic rays with the highest-energies so far detected has been a great challenge ever since the first event with energy around 1020 eV was reported [2]. If the highest-energy cosmic rays are predominantly protons and nuclei, only sources which are less than abo ...
A marked correlation function for constraining
... plotted s2 [1 − M], which we see is qualitatively similar to r2 ξ as might be expected by the structure of the terms (see below). To gain some intuition let us consider just the lowest order term, linear in B1 (still with b1 = b2 = 0). This term is −2B1 UiR gi . Recalling that UiR = hδR ∆i i we see ...
... plotted s2 [1 − M], which we see is qualitatively similar to r2 ξ as might be expected by the structure of the terms (see below). To gain some intuition let us consider just the lowest order term, linear in B1 (still with b1 = b2 = 0). This term is −2B1 UiR gi . Recalling that UiR = hδR ∆i i we see ...
Laser Interferometer Space Antenna “Listening to the Universe with
... – Like measuring the distance between ...
... – Like measuring the distance between ...
Diffusion of cosmic rays at EeV energies in
... fuzzy. From the theoretical point of view it is difficult to accelerate galactic cosmic rays up to 1018 eV through standard shock acceleration mechanisms. On the other hand, if the second knee marks the end of the galactic cosmic ray spectrum, one would need a new class of sources accelerating light ...
... fuzzy. From the theoretical point of view it is difficult to accelerate galactic cosmic rays up to 1018 eV through standard shock acceleration mechanisms. On the other hand, if the second knee marks the end of the galactic cosmic ray spectrum, one would need a new class of sources accelerating light ...
The Universe
... that expanded into the present-day universe according to the Hubble relation Refinements over several decades transformed the primeval atom hypothesis of Lemaitre into the Big Bang theory that is accepted today as the broad collection of theories that best describes the formation of the observable u ...
... that expanded into the present-day universe according to the Hubble relation Refinements over several decades transformed the primeval atom hypothesis of Lemaitre into the Big Bang theory that is accepted today as the broad collection of theories that best describes the formation of the observable u ...
Our galaxy is the centre of the universe, `quantized` redshifts show
... other only if our viewing location is less than a million light years from the centre. The odds for the Earth having such a unique position in the cosmos by accident are less than one in a trillion. Since big bang theorists presuppose the cosmos has naturalistic origins and cannot have a unique cent ...
... other only if our viewing location is less than a million light years from the centre. The odds for the Earth having such a unique position in the cosmos by accident are less than one in a trillion. Since big bang theorists presuppose the cosmos has naturalistic origins and cannot have a unique cent ...
Ch. 22
... lies beyond the portions of the galaxy that we can see. a. Yes, because the orbital velocity of gas and stars remains fairly constant as we look farther from the galactic center, even beyond where most stars are found. b. Yes, because dark matter telescopes show massive halos well beyond where stars ...
... lies beyond the portions of the galaxy that we can see. a. Yes, because the orbital velocity of gas and stars remains fairly constant as we look farther from the galactic center, even beyond where most stars are found. b. Yes, because dark matter telescopes show massive halos well beyond where stars ...
The Big Bang and Stellar Evolution
... an empty void cannot magically change itself into matter. Third, there can be no heat without an energy source. 7 – The calculations are too exacting. Too perfect an explosion would be required. On many points, the theoretical mathematical calculations needed to turn a Big Bang into stars and our pl ...
... an empty void cannot magically change itself into matter. Third, there can be no heat without an energy source. 7 – The calculations are too exacting. Too perfect an explosion would be required. On many points, the theoretical mathematical calculations needed to turn a Big Bang into stars and our pl ...
1 A CLOSED NON-COLLAPSING 3-D UNIVERSE PREDICTING A
... expansion to a halt and then accelerates its collapse back to a point. With the new idea of the condensation of a higher dimensional space to produce an ever-expanding 4-D ball, gravity has no effect whatsoever on the expansion rate and can only form dimples in the surface of the 4-D core. So a new ...
... expansion to a halt and then accelerates its collapse back to a point. With the new idea of the condensation of a higher dimensional space to produce an ever-expanding 4-D ball, gravity has no effect whatsoever on the expansion rate and can only form dimples in the surface of the 4-D core. So a new ...
2 Gamma-Ray Production and Absorption Processes
... the electrons at comparatively large distances (which are seen by γ-rays as almost independent from the nucleus). The atom is mostly ‘empty space’ for a γ-ray photon; interactions occur upon relatively low probability encounters with the nucleus or electrons. It is more appropriate to view γ-rays as ...
... the electrons at comparatively large distances (which are seen by γ-rays as almost independent from the nucleus). The atom is mostly ‘empty space’ for a γ-ray photon; interactions occur upon relatively low probability encounters with the nucleus or electrons. It is more appropriate to view γ-rays as ...
What We Might Learn from Gravitational Waves
... measure masses, spins, geometry EM: teaches us about the astrophysics measure energy, baryonic timescale, beaming, environment ...
... measure masses, spins, geometry EM: teaches us about the astrophysics measure energy, baryonic timescale, beaming, environment ...
Kosovichev - Physics - New Jersey Institute of Technology
... Evaluate various Hertzsprung-Russell diagrams for different types of star clusters. Analyze the evolution of binary star systems. Describe Einstein’s model of the universe (both the special relativity and the general relativity theories). Describe the properties of the Milky Way galaxy. Analyze othe ...
... Evaluate various Hertzsprung-Russell diagrams for different types of star clusters. Analyze the evolution of binary star systems. Describe Einstein’s model of the universe (both the special relativity and the general relativity theories). Describe the properties of the Milky Way galaxy. Analyze othe ...
Neutrinos in an Expanding Universe Paper (IOP)
... Since neutrinos are subject to gravitational forces, their spectra were affected by this developing nonuniformity. The neutrino velocities either increased or decreased as a result of gravitational acceleration or deceleration, depending on the direction of motion of the particles with respect to th ...
... Since neutrinos are subject to gravitational forces, their spectra were affected by this developing nonuniformity. The neutrino velocities either increased or decreased as a result of gravitational acceleration or deceleration, depending on the direction of motion of the particles with respect to th ...
Major Themes of “ The First Stars ”
... and/or metal enrichment metals, dust, CMB, other factors (?) How did the first and second stars form, and what was their IMF? Stellar Evolution and Nucleosynthesis of the First Stars: Approach: numerical stellar evolution and supernova models (1-D) Key Results: “Pair Instability SNe” and “Hypernovae ...
... and/or metal enrichment metals, dust, CMB, other factors (?) How did the first and second stars form, and what was their IMF? Stellar Evolution and Nucleosynthesis of the First Stars: Approach: numerical stellar evolution and supernova models (1-D) Key Results: “Pair Instability SNe” and “Hypernovae ...
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.