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Use of the Lorentz-operator in relativistic quantum mechanics to guarentee a single-energy root

Description: The Lorentz-operator form of relativistic quantum mechanics, with relativistic wave equation i{h_bar}{partial_derivative}{psi}/{partial_derivative}t=(mc{sup 2}{gamma}+e{Phi}){psi}, is implemented to guarantee a single-energy root. The Lorentz factor as modified by Pauli's ansatz is given by {gamma}={radical}1+[{rvec {sigma}}{center_dot}(i{h_bar}{rvec {del}}+(e/c){rvec A})]{sup 2}/m{sup 2}c{sup 2}, such that the theory is appropriate for electrons. Magnetic fine structure in the Lorentz relativistic wave equation emerges on the use of an appropriate operator form of the Lienard-Wiechert four- potential ({Phi},{rvec A}) from electromagnetic theory. Although computationally more intensive the advantage of the theory is the elimination of the negative-root of the energy and an interpretation of the wave function based on a one-particle, positive definite probability density like that of nonrelativistic quantum mechanics.
Date: August 1, 1998
Creator: Ritchie, A B
Partner: UNT Libraries Government Documents Department

Computing spacetime curvature via differential-algebraic equations

Description: The equations that govern the behavior of physical systems can often solved numerically using a method of lines approach and differential-algebraic equation (DAE) solvers. For example, such an approach can be used to solve the Einstein field equations of general relativity, and thereby simulate significant astrophysical events. In this paper, we describe some preliminary work in which two model problems in general relativity are formulated, spatially discretized, and then numerically solved as a DAE. In particular, we seek to reproduce the solution to the spherically symmetric Schwarzschild spacetime. This is an important testbed calculation in numerical relativity since the solution is the steady-state for the collision of two (or more) non-rotating black holes. Moreover, analytic late-time properties of the Schwarzschild spacetime are well known and can be used the accuracy of the simulation.
Date: January 1, 1996
Creator: Ashby, S.F.; Lee, S.L.; Petzold, L.R.; Saylor, P.E. & Seidel, E.
Partner: UNT Libraries Government Documents Department

Bergson and the unification of the sciences

Description: Louis De Broglie and M. Capek have described some interesting similarities between the philosophical ideas of Henri Bergson and the profound conceptual changes introduced into physics by quantum theory and the theory of relativity. These similarities are neither identities nor direct causal links, and hence physicists are likely to regard them as mere curiosities having no import for the development of science. However, another view is possible: if Bergson's thinking presaged, at least in spirit, these two revolutionary advances in physics then his intuitions may accord sufficiently with nature to provide useful guidance in the approach to other deep problems in science. Pursuing this idea I shall indicate here how Bergson's intuitions suggest a possible approach to perhaps the fundamental problem of contemporary science, namely the problem of constructing an overarching theoretical framework for unifying the various branches of science from psychology through biology to physics. 19 refs.
Date: February 1, 1985
Creator: Stapp, H.P.
Partner: UNT Libraries Government Documents Department

On the discrete reconciliation of relativity and quantum mechanics

Description: A way is sketched to replace physics based on arbitrary units of mass, length, and time by counting in terms of these quantized values and to replace continuum mathematical physics by computer science. The consequences of such a discrete physics are summarized. These are obtained by postulating finiteness, discreteness, finite computability, absolute non-uniqueness, and additivity. (LEW)
Date: March 1, 1987
Creator: Noyes, H.P.
Partner: UNT Libraries Government Documents Department


Description: A class of exact solutions to the Vlasov equations which shows electromagnetic radiation is constructed, and a typical example discussed in some detail. Since velocities larger than c appear to be possibly of importance in these solutions, an exact radiating solution to the relativistic Vlasov equations is constructed, which, though much more specialized than the nonrelativistic solutions, shows that unphysically large velocities in the nonrelativistic solutions are not essential for the radiation there obtained. (auth)
Date: December 11, 1959
Creator: Biedenharn, L.C.
Partner: UNT Libraries Government Documents Department


Description: Kinematic quantities are plotted as a function of particle momentum for the most common elementary particles. Dynamic quantities as a function of incident-particle momentum are plotted for interactions of most of these particles with a proton. Some techniques of relativistic kinematics are also included. (D.C.W.)
Date: July 1, 1963
Creator: Trower, W.P.
Partner: UNT Libraries Government Documents Department

Accretion onto black holes: The power generating mechanism

Description: This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The physical relationships among accretion disks, quasars, black holes, collimated radio sources and galactic dynamos previously has been only weakly related without explicit cause and effect. We have constructed a physical evolution from large, primordial density perturbations to {open_quotes}damped Lyman alpha clouds,{close_quotes} to galaxy formation, to black holes, jets, and the the galactic dynamo. We have derived the general relativistic distortions of radiation emitted from close to the black hole and thereby have a new observational test of the central engine. The physics of accretion disks, the astrophysical dynamo, and magnetic reconnection are the least understood physical phenomena in astrophysics. They are still less understood in the general relativity (GR) field close to the black hole. This lack of physical understanding frustrates a quantitative evaluation of observations that define the evolution from the early universe to star formation. We have made progress in this understanding.
Date: December 31, 1998
Creator: Colgate, S.A.; Hills, J.G. & Miller, W.A.
Partner: UNT Libraries Government Documents Department

Quark-antiquark bound states in the relativistic spectator formalism

Description: The quark-antiquark bound states are discussed using the relativistic spectator (Gross) equations. A relativistic covariant framework for analyzing confined bound states is developed. The relativistic linear potential developed in an earlier work is proven to give vanishing meson {r_arrow} q + {anti q} decay amplitudes, as required by confinement. The regularization of the singularities in the linear potential that are associated with nonzero energy transfers (i.e. q{sup 2} = 0, q{sup {mu}} {ne} 0) is improved. Quark mass functions that build chiral symmetry into the theory and explain the connection between the current quark and constituent quark masses are introduced. The formalism is applied to the description of pions and kaons with reasonable results.
Date: November 1, 1999
Creator: Savkli, Cetin & Gross, Franz
Partner: UNT Libraries Government Documents Department

Revised Theory of Transient Mass Fluctuations

Description: Several publications during the last 10 years by Woodward and colleagues have: (1) indicated a theory based on special relativity, that predicted transient mass fluctuations; (2) cited specific embodiments where a net average force would be present; (3) suggested a few ways that this theory might be tested in the laboratory; and (4) reported such test results incorporating these embodiments, which are interpreted to support theory (1) to (3) above. In this paper we show that: (1) the average force predicted by Woodward's theory occurred only because of a neglected term in a product derivative, and that when the neglected term is correctly returned, the average force identically vanishes; (2) this vanishment of the average force occurs for arbitrary forcing functions, not just the sinusoidal one considered by Woodward; (3) the transient mass fluctuation, predicted by Woodward, was developed in a theory which neglected local gravitational forces which are several dozen orders of magnitude greater; (4) additionally considering the dominant local gravitational forces produces a vastly smaller transient mass fluctuation; (5) several inconsistencies between Woodward's referents and the development of his wave equation lead to a formulation that does not follow from the antecedents even in the absence of the demonstrations (1) to (4) above; (6) there is an alternate interpretation of the Woodward/Mahood experiments that can entirely explain the findings in terms of force contributions due to time varying thermal expansion, without invoking any general relativistic effects; and (7) a laboratory demonstration of the alternate interpretation produced 100 times the Woodward effect without resort to non-Newtonian explanations.
Date: September 4, 2001
Creator: Whealton, J.H.
Partner: UNT Libraries Government Documents Department

Heavy mesons in a relativistic model

Description: Motivated by the present interest in the heavy quark effective theory, the authors use the spectator equations to treat the mesonic bound states of heavy quarks. The kernel they use is based on scalar confining and vector Coulomb potentials. Wave functions are treated to leading order and energies to order 1/m{sub Q} in the heavy-light systems, and order 1/m{sub Q{sup 2}} in heavy-heavy systems. Their results are in reasonable agreement with experimental measurements. They estimate two of the parameters of the heavy quark effective theory, and propose further calculations that may be undertaken in the future.
Date: December 1, 1994
Creator: Zeng, J.; Orden, J. & Roberts, W.
Partner: UNT Libraries Government Documents Department

The effects of general relativity on core collapse supernovae

Description: The effects of general relativity (GR) on the hydrodynamics and neutrino transport are examined during the critical shock reheating phase of core collapse supernovae. The authors find that core collapse computed with GR hydrodynamics results in a substantially more compact core structure out to the shock, the shock radius at stagnation being reduced by a factor of 2. The inflow speed of material behind the shock is also increased by a factor of 2 throughout most of the evolution. They have developed a code for general relativistic multigroup flux-limited diffusion (MGFLD) in static spacetimes and compared the steady-state neutrino distributions for selected time slices of post-bounce models with those computed with Newtonian MGFLD. The GR transport calculations show the expected reductions in neutrino luminosities and rms energies from redshift and curvature effects. Although the effects of GR on the hydrodynamics and neutrino transport seem to work against shock revival, the core configurations are sufficiently different that no firm conclusions can be drawn, except that simulations of core collapse supernovae using Newtonian hydrodynamics and transport are not realistic.
Date: December 1, 1997
Creator: De Nisco, K. R.; Bruenn, S. W. & Mezzacappa, A.
Partner: UNT Libraries Government Documents Department

E=mc{sup 2}: A hands-on exploration of Einstein's famous formula. Technical Report, 09/01/92-03/04/98

Description: The finished product is a museum exhibition of approximately 600 sq.ft. It consists of three exhibit elements and a colorful enclosure with text explanations, diagrams and photos. The combined exhibit elements, including an original video, explain in a hands-on, interactive way, the meaning of Einstein's famous equation E=mc{sup 2}.
Date: February 3, 2000
Creator: Malamud, Dr. Ernest; Snow, Dr. Gregory & O'Connor, Charles
Partner: UNT Libraries Government Documents Department

Low energy theorem for scalar and vector interactions of a composite spin-1/2 system

Description: Scalar and vector interactions, with the scalar interaction coupled to a composite spin-1/2 system so as to cause a shift of its mass, are shown to obey a low-energy theorem which guarantees that the second order interaction due to z-graphs is the same as for a point Dirac particle. Off-shell and contact interactions appropriate to the composite system cancel and this is verified in a model of a composite fermion. The result provides a justification for the use of the Dirac equation as it has been in relativistic nuclear scattering and mean field theories.
Date: July 1, 1994
Creator: Wallace, S. J.; Gross, Franz & Tjon, J. A.
Partner: UNT Libraries Government Documents Department

Relativistic calculation of the triton binding energy and its implications

Description: First results for the triton binding energy obtained from the relativistic spectator or Gross equation are reported. The Dirac structure of the nucleons is taken into account. Numerical results are presented for a family of realistic OBE models with off-shell scalar couplings. It is shown that these off-shell couplings improve both the fits to the two-body data and the predictions for the binding energy.
Date: July 1, 1996
Creator: Stadler, Alfred & Gross, Franz
Partner: UNT Libraries Government Documents Department

E. Cartan moment of rotation in classical and quantum gravity. Final report

Description: The geometric construction of the E. Cartan moment of rotation associated to the spacetime curvature provides a geometric interpretation of the gravitational field sources and describes geometrically how the sources are ``wired`` to the field in standard geometrodynamics. E. Cartan moment of rotation yields an alternate way (as opposed to using variational principles) to obtain Einstein equations. The E. Cartan construction uses in an essential way the soldering structure of the frame bundle underlying the geometry of the gravitational field of general relativity. The geometry of Ashtekar`s connection formulation of gravitation theory is based on a complex-valued self-dual connection that is defined not on the frame bundle of spacetime but, rather, on its complexification. We show how to transfer the construction of the E. Cartan moment of rotation to Ashtekar`s theory of gravity and demonstrate that no spurious equations are produced via this procedure.
Date: May 25, 1994
Creator: Kheyfets, A.
Partner: UNT Libraries Government Documents Department