Dark Matter Candidates - SLAC
... The lower bound on the mass of a fermionic dark matter particle is much more stringent than that for bosons. As first pointed out in Ref. [14], the phase space density of fermions has a maximum value f = gh−3 , where g is the number of internal degrees of freedom, and in fact for a relativistic gas o ...
... The lower bound on the mass of a fermionic dark matter particle is much more stringent than that for bosons. As first pointed out in Ref. [14], the phase space density of fermions has a maximum value f = gh−3 , where g is the number of internal degrees of freedom, and in fact for a relativistic gas o ...
1 Solutions to Problem Set 3, Physics 370, Spring 2014
... of this problem, the Gaussian surface is an arbitrary choice we make. So we typically try to exploit the symmetries in the charge distribution (or rather, in the electric field we expect from such a charge distribution) by selecting a Gaussian surface that lies perpendicular (or parallel) to the ele ...
... of this problem, the Gaussian surface is an arbitrary choice we make. So we typically try to exploit the symmetries in the charge distribution (or rather, in the electric field we expect from such a charge distribution) by selecting a Gaussian surface that lies perpendicular (or parallel) to the ele ...
Dark Matter: A Primer
... and more mass in enclosed, then the gravitational field will grow; here velocities can grow or remain constant as a function of radius r (with the exact behavior depending on the mass profile M (r)). If, however, the mass enclosed decreases or remains constant as the Gaussian surface grows, then the ...
... and more mass in enclosed, then the gravitational field will grow; here velocities can grow or remain constant as a function of radius r (with the exact behavior depending on the mass profile M (r)). If, however, the mass enclosed decreases or remains constant as the Gaussian surface grows, then the ...
Feshbach Resonance and Hybrid Atomic/Molecular BEC
... and displays the liquid-like property of a self-determined density. Interestingly the value of this density (or, alternatively, the volume) is determined by the detuning and can be varied by changing the magnetic field. In Fig.(3), we show the trajectory that the condensate follows in the plane of t ...
... and displays the liquid-like property of a self-determined density. Interestingly the value of this density (or, alternatively, the volume) is determined by the detuning and can be varied by changing the magnetic field. In Fig.(3), we show the trajectory that the condensate follows in the plane of t ...
Cosmic Order out of Primordial Chaos Jones, Bernard JT
... Summary. Nikos Voglis had many astronomical interests, among them was the question of the origin of galactic angular momentum. In this short tribute we review how this subject has changed since the 1970’s and how it has now become evident that gravitational tidal forces have not only caused galaxies ...
... Summary. Nikos Voglis had many astronomical interests, among them was the question of the origin of galactic angular momentum. In this short tribute we review how this subject has changed since the 1970’s and how it has now become evident that gravitational tidal forces have not only caused galaxies ...
Curtis/Shapley Debate – 1920 - Tufts Institute of Cosmology
... If you have a telescope or another means of seeing fainter objects, the situation changes completely. But astronomers did not always have telescopes. Humanity didn't always know the limits of our Galaxy and the existence of other galaxies - this knowledge came only this century - what was thought p ...
... If you have a telescope or another means of seeing fainter objects, the situation changes completely. But astronomers did not always have telescopes. Humanity didn't always know the limits of our Galaxy and the existence of other galaxies - this knowledge came only this century - what was thought p ...
Physics 416G : Solutions for Problem set 7
... The z-axis coincides with the symmetry axis of a flat disk of radius a in the x−y plane. The disk carries a uniform charge per unit area σ < 0. The rim of the disk carries an additional uniform charge per unit length λ > 0. Use a side (edge) view and sketch the electric field lines everywhere assumi ...
... The z-axis coincides with the symmetry axis of a flat disk of radius a in the x−y plane. The disk carries a uniform charge per unit area σ < 0. The rim of the disk carries an additional uniform charge per unit length λ > 0. Use a side (edge) view and sketch the electric field lines everywhere assumi ...
Interference of dark matter solitons and galactic offsets
... their collisional dynamics, and, in the ψ DM model, it is important for galactic mergers. This phase is ultimately determined by initial conditions at galactic formation. Moreover, the relative phase for any pair solitons changes in time since the propagation constant β depends on the mass, Eq. (10) ...
... their collisional dynamics, and, in the ψ DM model, it is important for galactic mergers. This phase is ultimately determined by initial conditions at galactic formation. Moreover, the relative phase for any pair solitons changes in time since the propagation constant β depends on the mass, Eq. (10) ...
Computing Quark and Gluon Distribution Functions for Very Large
... functions to smaller values of kt by including non-perturbative effects computable in weak coupling. We also argue that the power dependence of the distribution functions in Bjorken x may be modified in higher orders of perturbation theory. The outline of this paper is as follows: In the second sect ...
... functions to smaller values of kt by including non-perturbative effects computable in weak coupling. We also argue that the power dependence of the distribution functions in Bjorken x may be modified in higher orders of perturbation theory. The outline of this paper is as follows: In the second sect ...
Cosmic Strings - University of Amsterdam
... and domain walls can also occur. In the context of the Abelian-Higgs model, a simple formulation of a cosmic string will be derived. There are several ways to detect cosmic strings. In this thesis observational effects due to gravitational lensing and gravitational waves will be discussed. Using Gen ...
... and domain walls can also occur. In the context of the Abelian-Higgs model, a simple formulation of a cosmic string will be derived. There are several ways to detect cosmic strings. In this thesis observational effects due to gravitational lensing and gravitational waves will be discussed. Using Gen ...
Magnificent Cosmos - Academic Program Pages at Evergreen
... the star 70 Virginis, a similar object with a mass 6.8 times that of Jupiter. The objects orbiting both HD114762 and 70 Virginis are so large that most astronomers are not sure whether to consider them big planets or small brown dwarfs, entities whose masses lie between those of a planet and a star. ...
... the star 70 Virginis, a similar object with a mass 6.8 times that of Jupiter. The objects orbiting both HD114762 and 70 Virginis are so large that most astronomers are not sure whether to consider them big planets or small brown dwarfs, entities whose masses lie between those of a planet and a star. ...
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 ...
Effects of topological defects and local curvature on the electronic
... theoretical point of view, graphene has received a lot of attention in the past because it constitutes a beautiful and simple model of correlated electrons in two dimensions with unexpected physical properties[3]. A tight-binding method applied to the honeycomb lattice allows to describe the low ene ...
... theoretical point of view, graphene has received a lot of attention in the past because it constitutes a beautiful and simple model of correlated electrons in two dimensions with unexpected physical properties[3]. A tight-binding method applied to the honeycomb lattice allows to describe the low ene ...
of satellite data, and associated opportunities for the LHC
... Over two decades ago recognized that one way to “see” dark matter was via products of annihilation of pairs of DM particles in the galaxy Traditionally the lightest superpartner, LSP, a very good DM candidate Annihilate into everything, but positrons, antiprotons, gammas should be easier to s ...
... Over two decades ago recognized that one way to “see” dark matter was via products of annihilation of pairs of DM particles in the galaxy Traditionally the lightest superpartner, LSP, a very good DM candidate Annihilate into everything, but positrons, antiprotons, gammas should be easier to s ...
Quasar Formation and Energy Emission in Black Hole Universe
... other and further into the massive black hole at the center and meantime release a huge amount of radiation energy that can be as great as that of a quasar. Therefore, when the stellar black holes of a galaxy collapse and merge into a supermassive black hole, the galaxy is activated and a quasar is ...
... other and further into the massive black hole at the center and meantime release a huge amount of radiation energy that can be as great as that of a quasar. Therefore, when the stellar black holes of a galaxy collapse and merge into a supermassive black hole, the galaxy is activated and a quasar is ...
1 PROBLEM SET-5 (Current and Resistance) 1- A
... 1- A teapot with a surface area of 700 cm2 is to be silver plated. It is attached to the negative electrode of an electrolytic cell containing silver nitrate (Ag+ NO3–). If the cell is powered by a 12.0-V battery and has a resistance of 1.80 Ω, how long does it take for a 0.133-mm layer of silver to ...
... 1- A teapot with a surface area of 700 cm2 is to be silver plated. It is attached to the negative electrode of an electrolytic cell containing silver nitrate (Ag+ NO3–). If the cell is powered by a 12.0-V battery and has a resistance of 1.80 Ω, how long does it take for a 0.133-mm layer of silver to ...
Dark Matter, Dark Energy, and the Fate of the Universe
... We might naively think that the major source of gravity that holds galaxies together should be the same gas that makes up their stars. However, observations suggest otherwise. By carefully observing gravitational effects on matter that we can see, Dark matter is the name given to mass that such as ...
... We might naively think that the major source of gravity that holds galaxies together should be the same gas that makes up their stars. However, observations suggest otherwise. By carefully observing gravitational effects on matter that we can see, Dark matter is the name given to mass that such as ...
Introduction to Dark Matter
... photons, and the Universe became transparent to radiation. The Black body radiation originating from this cosmic plasma is still permeating the Universe in the form of the Cosmic Microwave Background Radiation (CMBR; often referred to as the “afterglow” of Big Bang) which can be observed at T ≈ 2.73 ...
... photons, and the Universe became transparent to radiation. The Black body radiation originating from this cosmic plasma is still permeating the Universe in the form of the Cosmic Microwave Background Radiation (CMBR; often referred to as the “afterglow” of Big Bang) which can be observed at T ≈ 2.73 ...
THE ELECTRON DENSITY DISTRIBUTION IN THE HYDROGEN
... The calculations on the water molecule in an electric field, on the water dimer, and on the oxalic acid dihydrate were performed within the framework of the density-functional theory. This is equivalent to solving the HartreeFock equations with an approximate exchange-correlation potential for which ...
... The calculations on the water molecule in an electric field, on the water dimer, and on the oxalic acid dihydrate were performed within the framework of the density-functional theory. This is equivalent to solving the HartreeFock equations with an approximate exchange-correlation potential for which ...
PDF only
... primeval photon. We will make this our first postulate. The second being that if space is not infinitely divisible into position coordinates, only a single position coordinate will be available at the Planck size ~ 1.616 •10-35m. There is nothing outside of the primeval photon, so any continued evol ...
... primeval photon. We will make this our first postulate. The second being that if space is not infinitely divisible into position coordinates, only a single position coordinate will be available at the Planck size ~ 1.616 •10-35m. There is nothing outside of the primeval photon, so any continued evol ...
Cold galaxies at low and high z
... Over 100 Type Ia supernova have been found at redshifts 0.5-1.5 Comparing these to nearby supernova, we find that in cosmological models with matter only, the distant supernovae are fainter than expected for their redshift (Perlmutter 2002). ‘Dark energy’ is pushing the galaxies apart. Sept 27th 200 ...
... Over 100 Type Ia supernova have been found at redshifts 0.5-1.5 Comparing these to nearby supernova, we find that in cosmological models with matter only, the distant supernovae are fainter than expected for their redshift (Perlmutter 2002). ‘Dark energy’ is pushing the galaxies apart. Sept 27th 200 ...
Problem 5.1 An ideal gas occupies a volume of 100 cm at 20°C and
... A sample of helium behaves as an ideal gas as energy is added by heat at constant pressure from 273 K to 373 K. If the gas does 20.0 J of work, what is the mass of helium present? ...
... A sample of helium behaves as an ideal gas as energy is added by heat at constant pressure from 273 K to 373 K. If the gas does 20.0 J of work, what is the mass of helium present? ...
Answering the Fermi Paradox - Acceleration Studies Foundation
... and pyrimidines), make increasingly convincing arguments that the third and fourth terms are also quite large. But when we get to the fourth term, the probability of biogenesis, we run into the second major camp, the biologists. Everyone in this group has been educated with, and many have come to ac ...
... and pyrimidines), make increasingly convincing arguments that the third and fourth terms are also quite large. But when we get to the fourth term, the probability of biogenesis, we run into the second major camp, the biologists. Everyone in this group has been educated with, and many have come to ac ...
Flatness problem
The flatness problem (also known as the oldness problem) is a cosmological fine-tuning problem within the Big Bang model of the universe. Such problems arise from the observation that some of the initial conditions of the universe appear to be fine-tuned to very 'special' values, and that a small deviation from these values would have had massive effects on the nature of the universe at the current time.In the case of the flatness problem, the parameter which appears fine-tuned is the density of matter and energy in the universe. This value affects the curvature of space-time, with a very specific critical value being required for a flat universe. The current density of the universe is observed to be very close to this critical value. Since the total density departs rapidly from the critical value over cosmic time, the early universe must have had a density even closer to the critical density, departing from it by one part in 1062 or less. This leads cosmologists to question how the initial density came to be so closely fine-tuned to this 'special' value.The problem was first mentioned by Robert Dicke in 1969. The most commonly accepted solution among cosmologists is cosmic inflation, the idea that the universe went through a brief period of extremely rapid expansion in the first fraction of a second after the Big Bang; along with the monopole problem and the horizon problem, the flatness problem is one of the three primary motivations for inflationary theory.