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NASA NTRS2018

Challenges Beyond the Standard Model: An Examination and Evaluation of Alternatives with Respect to Unsolved Problems in Energetics and Signaling

The standard model of particle physics is regarded as one of the greatest achievements of modern physics. It has successfully predicted the existence of numerous hadrons; e.g. the Higgs Boson, the W and Z Bosons, B mesons, etc. Moreover it accurately models many phenomena such as Beta and Radioactive decay, pair production, hadron mass splitting, and others. In spite of this, the standard model has many shortfalls. For example it fails to account for or explain the presence of dark matter and dark energy. Many alternative models of the substructure of matter etc. have been proposed. Some of these are examined. In addition the strongly related standard model of cosmology, that is the big bang theory, accounts for all observed celestial phenomena. What it cannot do is satisfactorily justify all astrophysical events. As noted, dark matter and dark energy are not well understood yet they are core elements of the big bang model. Many elements of this standard model of cosmology are challenged regularly, yet somehow the community always fits the problems with the model into another mysterious element. This model and others are examined for consistency and reconciliation. Evidence of particles that move faster than the speed of light has long been sought, but remains elusive. Some of the known space-like observations of physics are examined. Potential consequences of such particles are likewise investigated. Some conclusions are drawn with respect to the framework of tachyons in a rational but non-rigorous sense. Finally, some of my ideas are presented, concerning all of the above material. The framework of theories of everything is examined, considering what such a theory requires for validity. Sociological notes on the structure of research in physics are given.

Coxe, Alexander M.↗
NASA NTRS1981

Particle physics in the very early universe

Events in the very early big bang universe in which elementary particle physics effects may have been dominant are discussed, with attention to the generation of a net baryon number by way of grand unification theory, and emphasis on the possible role of massive neutrinos in increasing current understanding of various cosmological properties and of the constraints placed on neutrino properties by cosmology. It is noted that when grand unification theories are used to describe very early universe interactions, an initially baryon-symmetrical universe can evolve a net baryon excess of 10 to the -9th to 10 to the -11th per photon, given reasonable parameters. If neutrinos have mass, the bulk of the mass of the universe may be in the form of leptons, implying that the form of matter most familiar to physical science may not be the dominant form of matter in the universe.

Schramm, D. N.↗
NASA NTRS1979

Globally baryon symmetric cosmology, GUT spontaneous symmetry breaking, and the structure of the universe

Grand unified theories (GUT) such as SU(5), with spontaneous symmetry breaking, can lead more naturally to a globally baryon symmetric big bang cosmology with a domain structure than to a totally asymmetric cosmology. The symmetry is broken at random in causally independent domains, favoring neither a baryon nor an antibaryon excess on a universal scale. Because of the additional freedom in the high-energy physics allowed by such GUT gauge theories, new observational tests may be possible. Arguments in favor of this cosmology and various observational tests are discussed.

Stecker, F. W.↗
NASA NTRS2010

Inertia and Double Bending of Light from Equivalence

Careful examination of light paths in an accelerated reference frame, with use of Special Relativity, can account fully for the observed bending of light in a gravitational field, not just half of it as reported in 1911. This analysis also leads to a Machian formulation of inertia similar to the one proposed by Einstein in 1912 and later derived from gravitational field equations in Minkowsky Space by Sciama in 1953. There is a clear inference from equivalence that there is some type of inertial mass increase in a gravitational field. It is the purpose of the current paper to suggest that equivalence provides a more complete picture of gravitational effects than previously thought, correctly predicting full light bending, and that since the theory of inertia is derivable from equivalence, any theory based on equivalence must take account of it. Einstein himself clearly was not satisfied with the status of inertia in GRT, as our quotes have shown. Many have tried to account for inertia and met with less than success, for example Davidson s integration of Sciama s inertia into GRT but only for a steady state cosmology [10], and the Machian gravity theory of Brans and Dicke [11]. Yet Mach s idea hasn t gone away, and now it seems that it cannot go away without also disposing of equivalence.

Shuler, Robert L., Jr.↗
NASA NTRS1980

Cosmological tests of the Hoyle-Narlikar conformal gravity

For the first time the Hoyle-Narlikar theory with creation of matter and a variable gravitational constant G, is subjected to the following cosmological tests: (1) the magnitude versus z relation, (2) the N(m) versus m relation for quasars, (3) the metric angular diameters versus z relation, (4) the isophotal angles versus z relation, (5) the log N-log S radio source count, and finally (6) the 3 K radiation. It is shown that the theory passes all these tests just as well as the standard cosmology, with the additional advantage that the geometry of the universe is uniquely determined, with a curvature parameter equal to zero. It is also interesting to note that the variability of G affects the log N-log S curve in a way similar to the density evolution introduced in standard cosmologies. The agreement with the data is therefore achieved without recourse to an ad hoc density evolution.

Canuto, V. M.↗
NASA NTRS1981

Grand unification and possible matter-antimatter domain structure in the universe

The theory and basic concepts for the development of a matter-antimatter domain cosmology are outlined within the framework of the grand unified gauge theory paradigm. It is shown how spontaneous CP symmetry breaking leads to such a domain sturcture in the universe. Astrophysical data such as the cosmic gamma-ray background spectrum, cosmic-ray p flux measurements, and galaxy clustering are found to favor this point of view. Future tests of this form of big-bang cosmology are suggested and discussed, including tests using deep underwater cosmic ray neutrino detectors.

Stecker, F. W.↗
NASA NTRS1972

Curved space cosmological bounds on the time variation of G.

Additional quantitative and revealing arguments are given in favor of author's previous suggestion (1971) that the introduction of pressure results in a decrease in the theoretical upper bound on the time variation of G, as predicted by the Brans-Dicke theory (1961) for Friedmann-type expanding cosmologies in flat space, and that this suggestion holds in curved spaces as well. Moreover, it is shown that the curvature contribution to G is of the same order of magnitude as the flat space contribution and adds to it or subtracts from it for positive or negative curvatures respectively.

Morganstern, R. E.↗
NASA NTRS1978

On the formation and evolution of clumps of galaxies in an expanding universe

Results are derived for the development of phase-space clumps of mass points in a background spectrum of gravitational-potential fluctuations. The Vlasov equation and the pair correlation equation (in the weak coupling limit) are solved exactly in an Einstein-de Sitter cosmology, and the plasma-clumping theory is used to identify terms that yield important collective effects. Various astrophysical implications are discussed, including the formation of large-scale inhomogeneity and the enhanced generation of correlations in the distribution of galaxies.

Norman, C. A.↗
NASA NTRS2011

The New Era of Precision Cosmology: Testing Gravity at Large Scales

Cosmic acceleration may be the biggest phenomenological mystery in cosmology today. Various explanations for its cause have been proposed, including the cosmological constant, dark energy and modified gravities. Structure formation provides a strong test of any cosmic acceleration model because a successful dark energy model must not inhibit the development of observed large-scale structures. Traditional approaches to studies of structure formation in the presence of dark energy ore modified gravity implement the Press & Schechter formalism (PGF). However, does the PGF apply in all cosmologies? The search is on for a better understanding of universality in the PGF In this talk, I explore the potential for universality and talk about what dark matter haloes may be able to tell us about cosmology. I will also discuss the implications of this and new cosmological experiments for better understanding our theory of gravity.

Prescod-Weinstein, Chanda↗
NASA NTRS2021

Physics and Chemistry of Te and HgTe-based Ternary Melts

Historically, the theoretical treatment of the liquid phases has always been more difficult and complicated than that for solid and gas phases. A liquid has no lattice structure as crystalline solids and the atoms/molecules in the liquid can migrate through it relatively rapidly. On the other hand, it is also interacting with many other atoms/molecules so that the simplifications of the kinetic theory of gases cannot be employed. For more complicated liquids, such as the liquids of high ionicity and those containing hydrogen bonds and electric dipoles, the understanding is far from complete. At the same time, accurate information on the physics and chemistry of semiconductor melts is needed for the quantitative descriptions of the process of crystal growth from melt. The pre-crystallization phenomena in the liquid phase are critical because the properties of the grown crystals depend on the state and structure of the melt as well as the thermal history of the melt during solidification process. However, the data on the liquid phase, such as thermophysical properties of semiconductor melts are scarce, especially for the HgTe-based II-VI ternary compound semiconductors because of their high vapor pressure and extreme toxicity. Analysis of the thermophysical properties of the melt can provide information about structural transitions of the melt during the solidification process. From a broader point of view, the structure of liquids is much more complicated than the crystalline solids, especially the relaxation behavior through different thermal histories. The theory of hetero-phase fluctuations of liquids is applicable to any many-body systems including condensed-matter physics, field theory, physics of nuclear-matter, cosmology, biology and even sociology. This book summarizes the physics and chemistry from the experimental measurements and theoretical analyses of phase diagram, thermodynamic properties, density, thermal conductivity, viscosity, and electrical conductivity on the binary, pseudo-binary and ternary melts of the most advanced IR-detector material systems of HgCdTe and HgZnTe as well as the analyses of these results. The main objectives of this study are: (1) to provide the phase diagrams and thermodynamic properties of Hg-Cd-Te and Hg-Zn-Te systems through quantitatively fitting the experimental data by assuming an associated solution model for the liquid phase, (2) to experimentally measure the thermophysical properties of the Hg-Cd-Te and Hg-Zn-Te melts, including density, viscosity, electrical conductivity and thermal conductivity as functions of temperature and composition and (3) to enhance the fundamental knowledge of hetero-phase fluctuations and relaxation phenomena in the melts and extend our understanding of the solidification process in order to interpret the experimental results of crystal growth so as to improve the melt growth processes of the compound semiconductor. The physics and chemistry of Te and HgTe-based ternary melts were explored through the studies of the structural transformation during melting, the supercooling during solidification, the relaxation phenomena after rapid cooling of the melts and the metal-semiconductor transition in the melts through the analyses of electrical conductivity and Lorenz number. An in-depth study on the thermophysical properties and their time-dependent structural dynamic processes taking place in the vicinity of the solid-liquid phase transition of the narrow homogeneity range HgTe-based ternary semiconductors as well as the analysis of the homogenization process in the melt will also be presented.

Thermophysical properties↗
NASA NTRS2018

Clockwork Axions in Cosmology. Is Chromonatural Inflation Chrononatural?

Many cosmological models rely on large couplings of axions to gauge fields. Examples include theories of magnetogenesis, inflation on a steep potential, chiral gravitational waves, and chromonatural inflation. Such theories require a mismatch between the axion field range and the mass scale appearing in the aFF~ coupling. This mismatch suggests an underlying monodromy, with the axion winding around its fundamental period a large number of times. We investigate the extent to which this integer can be explained as a product of smaller integers in a UV completion: in the parlance of our times, can the theory be “clockworked”? We argue that a clockwork construction producing a potential μ4cos(ajFa) for an axion of fundamental period Fa will obey the constraint μ < Fa. For a some applications, including chromonatural inflation with sub-Planckian field range, this constraint obstructs a clockwork UV completion. Alternative routes to a large coupling include fields of large charge (an approach limited by strong coupling) or kinetic mixing (requiring a lighter axion). Our results suggest that completions of axion cosmologies that explain the large parameter in the theory potentially alter the phenomenological predictions of the model.

Cosmology of Theories beyond the SM↗
NASA NTRS1981

Cosmic plasma

Attention is given to experimental and theoretical approaches to plasma physics, plasma phenomena in laboratory and space, field and particle aspects of plasmas, the present state of the classical theory, boundary conditions and circuit dependence, and cosmology. Electric currents in space plasmas are considered, taking into account dualism in physics, particle-related phenomena in plasma physics, magnetic field lines, filaments, local plasma properties and the circuit, electric double layers, field-aligned currents as 'cables', an expanding circuit, different types of plasma regions, the cellular structure of space, and the fine structure of active plasma regions. Other topics discussed are related to circuits, the theory of cosmic plasmas, the origin of the solar system, the coexistence of matter and antimatter, annihilation as a source of energy, the Hubble expansion in a Euclidean space, and a model for the evolution of the Metagalaxy.

Alfven, H.↗
NASA NTRS2004

Measuring the Mass Distribution in Z is Approximately 0.2 Cluster Lenses with XMM, HST and CFHT

Being the most massive gravitationally bound objects in the Universe, clusters of galaxies are prime targets for studies of structure formation and evolution. Specifically the comoving space density of virialized clusters of a given mass (or X-ray temperature), but also the frequency and degree of substructure, as well as the shape of the cluster mass profile are quantities whose current values and evolution as a function of lookback time can provide important constraints on the cosmological and physical parameters of structure formation theories. The project funded by NASA grant NAG 5-10041 intended to take such studies to a new level by combining observations of a well-selected cluster sample by three state-of-the-art telescopes: HST, to accurately measure the mass distribution in the cluster core (approx. 0.5 h(sup -1)(sub 50) Mpc) via strong gravitational lensing; CFHT, to measure the large scale mass distribution out to approx. 3 Mpc via weak lensing; and XMM, to measure the gas density and temperature distribution accurately on intermediate scales < 1.5 Mpc. XMM plays a pivotal role in this context as the calibration of X-ray mass measurements through accurate, spatially resolved X-ray temperature measurements (particularly in the cosmologically most sensitive range of kT> 5 keV) is central to the questions outlined above. This set of observations promised to yield the best cluster mass measurements obtained so far for a representative sample, thus allowing us to: 1) Measure the high-mass end of the local cluster mass function; 2) Test predictions of a universal cluster mass profile; 3) calibrate the mass-temperature and temperature-luminosity relations for clusters and the scatter around these relations, which is vital for studies of cluster evolution using the X-ray temperature and X-ray luminosity functions.

Source record↗
NASA NTRS1992

A photoionization instability in the early intergalactic medium

It is argued that any fairly uniform source of ionizing photons can be the cause of an instability in the pregalactic medium on scales larger than a photon path length. Underdense regions receive more ionizing energy per atom and reach higher temperature and entropy, driving the density down still further. Fluctuations created by this instability can lead to the formation of structures resembling protogalaxies and intergalactic clouds, obviating the need for gas clouds or density perturbations of earlier cosmological provenance, as is usually assumed in theories of galaxy and structure formation. Characteristic masses for clouds produced by the instability, with log mass in solar units plotted against log radius in kpc, are illustrated.

Hogan, Craig J.↗
NASA NTRS1981

Nucleocosmochronology

Nucleocosmochronology is analyzed on the basis of elemental isotopic abundances of radionuclides. The production and depletion mechanisms for the cosmological chronometers are investigated and model-independent theories are reviewed. Emphasis is given to the significance of the mean age of the elements and the time resolution of the last nucleosynthetic events contributing to the solar system, and it is shown how the intermediate-lived chronometers may give information on the time dependence shape of the production function. Anomalous nucleocosmochronology is investigated and galactic and cosmological constraints are described in terms of time scales for the mean age of elements and galaxies and the age of the universe. Data resulting from both model-independent and dependent analyses are compared. Results based on the mean age for the r-process elements suggest a lower limit to the age of the galaxy and the universe. It is concluded that nucleocosmochronology, when coupled with other independent determinations for the age of the universe, defines a concordant universe age of 13.5-15.5 billion years. The shape of the production function is not well determined because of the uncertainties in the xenon data.

Symbalisty, E. M. D.↗
NASA NTRS1992

Conformal gravity and the flatness problem

The radiation and matter-dominated cosmologies associated with fourth-order conformal Weyl gravity, a theory which is currently being explored as a candidate alternative to the standard second-order Einstein theory, are presented. The theory naturally yields an open though nonetheless recollapsing universe which can even oscillate indefinitely, which appears to possess no flatness problem, which has a cosmology which could potentially be created out of nothing, which is singularity free, and which does not appear to require any cosmological dark matter.

Mannheim, Philip D.↗
NASA NTRS1991

Basic physics and cosmology from pulsar timing data

Radio pulsars provide unparalleled opportunities for making measurements of astrophysically interesting phenomena. The author concentrates on two particular applications of high precision timing observations of pulsars: tests of relativistic gravitation theory using the binary pulsar 1913+16, and tests of cosmological models using timing data from millisecond pulsars. New upper limits are presented for the energy density of a cosmic background of low frequency gravitational radiation.

Taylor, J. H.↗