Bulletin of the American Physical Society
2009 APS March Meeting
Volume 54, Number 1
Monday–Friday, March 16–20, 2009; Pittsburgh, Pennsylvania
Session Y13: General Theoretical and Computational Methods |
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Sponsoring Units: DCOMP Chair: Christine Wu, Lawrence Livermore National Laboratory Room: 309 |
Friday, March 20, 2009 8:00AM - 8:12AM |
Y13.00001: A global EMC/FDTD simulation tool for modeling THz wave interaction with conductive media K. J. Willis, S. C. Hagness, I. Knezevic We present a computational tool for modeling the interaction between THz electromagnetic waves and conductive media. By coupling the ensemble Monte Carlo (EMC) simulator of carrier dynamics and the finite-difference time-domain (FDTD) solver of Maxwell's equations, we have developed a robust and versatile global simulator that interactively tracks the field-particle dynamics. The global simulator enables accurate numerical examination of wave propagation in conductive media under circumstances in which macroscopic materials properties are not well established, such as under THz-frequency wave irradiation of highly doped semiconductors. [Preview Abstract] |
Friday, March 20, 2009 8:12AM - 8:24AM |
Y13.00002: GPU Based Acceleration of First Principles Calculations Hidekazu Tomono, Toshiaki Iitaka, Kazuo Tsumuraya The saturation of the acceleration using the silicon devices has required the parallel computing using multiple CPU's (central processing units). The parallel computing has been widely used in the field of the high-performance computing. On the other hand, graphics processing units (GPU's) were designed to accelerate graphic applications in 1978. NVIDIA Co.\ began to provide CUDA for C-language users to manipulate the GPU's in 2007. They applied it to computational fluid dynamics, medical real time simulation and astronomical N-body problem among others. This is the GPGPU (general-purpose computation on GPU's), which is faster in operation than CPU in the fields of linear algebras, FFT, and others. We have experienced that one- dimensional CUFFT ver1.1 (GPU-FFT) is eight times faster than FFTW for single-precision case. We implement the GPU-FFT into our in-house first principles planewave code, in which the hot spot is the FFT routine. We will present the performance of the implementation. [Preview Abstract] |
Friday, March 20, 2009 8:24AM - 8:36AM |
Y13.00003: Saturation effects in dispersion interactions Bo E. Sernelius The interest in Casimir interactions has been very strong during the last decade. This increase in interest was spurred by the torsion pendulum experiment by Lamoreaux which produced results with good enough accuracy for the comparison between theory and experiment to be feasible. Theory and experiment agree quite well for low temperatures. However at room temperature, where most experiments are performed there are serious deviations. Each new experiment has lead to new puzzling discrepancies between theory and experiment. Theorists have been forced to resort to phenomenological approaches to the problems, with new prescriptions for each new experiment. Here we address three experiments: Casimir pressure between a gold sphere and a gold plate; Casimir force between a gold sphere and a laser excited silicon membrane; Casimir force between a Rb atom and a fused silica wall. In all these different experiments we show that inclusion of saturation effects makes the discrepancies go away. [Preview Abstract] |
Friday, March 20, 2009 8:36AM - 8:48AM |
Y13.00004: Symmetries of non-relativistic quantum-mechanical Hamiltonian Bojan Tunguz In non-relativistic quantum mechanics the most fundamental invariance group of the Hamiltonian is the Galilean group of transformations: the group spatial and temporal translations and rotations. The quantum-mechanical wave functions in that view belong to an infinite-dimensional representation of the Galilean group, and the generators are represented with first-order differential operators. In this work we look at all the higher order differential operators that commute with the Hamiltonian and construct the most general group that leaves the Hamiltonian invariant. We show how the Galilean group fits within this group, and we show how the interaction terms break the symmetry of the free-particle Hamiltonian. We argue that the interpretation of the Hamiltonian in terms of individual interacting particles is the consequence of this broken symmetry. [Preview Abstract] |
Friday, March 20, 2009 8:48AM - 9:00AM |
Y13.00005: Planck's High Temperature Catastrophe in Observational Astronomy:- (NASA proves Planck wrong) Clarence A. Gall Planck's black body radiation law $\left( I_{P}=\frac{c_{1}} {\lambda ^{5}}\frac{1}{e^{\frac{c_{2}}{\lambda T}}~~-1}\right) $predicts that a hotter body (higher T) should always emit more intensely than a colder body (lower T) throughout the entire EMR spectrum. However, space age infrared astronomy contradicts this prediction! It is now known that as observation moves from the visible to the near-, mid- and far infrared; increasingly cold celestial objects come into view while hotter ones fade and disappear (http://coolcosmos.ipac.caltech.edu/cosmic\_classroom/ir\_tutori al/irregions.html). Were Planck's law valid, the hottest stars would never disappear; and colder objects would not be detected. This can only be described as a high temperature catastrophe (BAPS, April Meeting 2008, H12.3, St Louis, MO) for Planck's law! On the other hand, Gall's black body radiation law $\left( I_{G}=\sigma \frac{T^{6}}{b^{2}}\lambda e^{-\frac {\lambda T}{b}}\right) $ (http://sites.google.com/site/purefieldphysics) predicts that as wavelength increases, there is a crossover point above which a colder object will emit more intensely than a hotter one. Hence colder objects will appear and hotter ones will eventually disappear from view. The crossover point for black bodies at 6000K and 100K is 12.066 microns. These calculations with Gall's law are in overall agreement with observational infrared astronomy. [Preview Abstract] |
Friday, March 20, 2009 9:00AM - 9:12AM |
Y13.00006: Expressing n dimensions as n-1 John Laubenstein The IWPD Scale Metrics team has explored a different conceptualization of multiple dimensions through a model expressing n dimensions as n -- 1. This is achieved by aligning time and a spatial dimension along the same orientation. We have shown that time and distance along the same axis in combination with a scalar is equivalent to two orthogonal dimensions. Scale Metrics is simply a different conceptualization of multi-dimensions; however, it requires a change in the modeling of gravitation since time is no longer considered to be orthogonal to the three spatial dimensions. A model for Scale Metrics gravity has been developed and in the process a quantum theory of gravitation emerges. Why entertain IWPD Scale Metrics? Because the Standard Model has not been successful in the unification of GR with QT. A new model of gravitation built on a foundation of quantum concepts (as opposed to a quantum fix to an inherently classical geometric theory) may be of benefit in the ultimate search for the unification of gravitation with quantum theory. Further, since Scale Metrics provides nothing more than a different way to conceptualize multiple dimensions in a manner that is equivalent to 4 vectors -- it replaces nothing, but rather serves only to complement past and current achievements while providing a new view of quantum gravitation. [Preview Abstract] |
Friday, March 20, 2009 9:12AM - 9:24AM |
Y13.00007: The mass, energy, space and time system theory-MEST- the theory of relativity and the quantum mechanics Dayong Cao Things have their own physical system of mass energy, space and time of themselves. (The MEST for short thereinafter) So we can use it to unite both the physical system of any thing. There are the transmutation between space-time and mass-energy. There are the conservation of space-time and mass-energy.The uf force like the gravitation is from space-time, the down force like repulsion is from mass-energy. So there are the positive and negative curvature. We need to develop the theory of relativity and get the new equation. By using the mass-energy wave equation, deduce the new uncertainty principle, uncertainty and probability can not be divided. New wave web equation are being put forward. The quantum mechanics is the mass and energy theory of relativity; the theory of relativity is the space and time theory of relativity. MEST can unite both them. [Preview Abstract] |
Friday, March 20, 2009 9:24AM - 9:36AM |
Y13.00008: Is Sound a Property of Space or Vacuum? Venkata Chaganti Absolutist regards SPACE as an entity in its own right with properties of its own. Further more, relationists, scientists and laymen attribute many different sorts of properties to SPACE. In fact, we are able to distinguish every material from the other by its properties. We all know that SPACE is attributed by some of the properties listed below. 1. Electromagnetic Properties like permittivity and permeability. 2. Empty SPACE is a poor conductor. 3. Empty SPACE is transparent. 4. SPACE is penetrable by any particle / material. 5. SPACE is incapable of action. 6. SPACE is immovable. 7. SPACE is infinite. 8. SPACE is isotropic. 9. All bodies are place in SPACE. 10. SPACE is Isotropic. And many more properties can be made quite precise without any reference to an embedding space surrounding the SPACE of interest. SPACE as a physical object only makes sense if it can be detected, or if it can exert physical influences. Does the motion of an object through SPACE lead to detectable effects? Can SPACE act on a moving body in the way that the sea acts on a moving fish? In this paper an attempt is made to show that SPACE is indeed like any other medium / material and also SOUND is its property. Statistical Mechanics is used as a tool. [Preview Abstract] |
Friday, March 20, 2009 9:36AM - 9:48AM |
Y13.00009: New Generally Covariant Generalization of the Dirac Equation Not Requiring Gauges David Maker We introduce a new pde ($\Sigma _{\mu }\surd \kappa _{\mu \mu }$\textit{$\gamma $}$_{\mu }$\textit{$\partial \psi $/$\partial $x}$_{\mu }$\textit{-$\omega \psi $=0}) with spherically symmetric diagonalized $\kappa _{00}$ = 1-r$_{H}$ =1/$\kappa _{rr}$ giving it general covariance. If r$_{H}$ =2e$^{2}$/m$_{e}$c$^{2}$ this new pde reduces to the standard Dirac equation as r$\to \infty $. Next we solve this equation directly using separation of variables (e.g., 2P, 2S, 1S terms). Note metric time component $\kappa _{oo}$=0 at r=r$_{H}$ and so clocks slow down with \textit{baryon stability} the result. Note also that near r$_{H}$ the 2P$_{3/2}$ state for this new Dirac equation gives a azimuthal trifolium, 3 lobe shape; so this \textbf{ONE} charge$ e$ (so don't need \textit{color} to guarantee this) spends $1/3$ of its time in each lobe (\textit{fractionally charged} lobes), the lobe structure is locked into the center of mass \textbf{(}\textit{asymptotic freedom}), there are \textit{six }2P states (corresponding to the 6 flavors);~the P wave scattering gives the \textit{jets}\textbf{,} all these properties together constituting the~\textit{main properties of quarks!}~without invoking the many free parameters, gauge conditions of QCD. Also the 2S$_{1/2}$ is the\textbf{ }\textit{tauon} and the 1S$_{\raise.5ex\hbox{$\scriptstyle 1$}\kern-.1em/ \kern-.15em\lower.25ex\hbox{$\scriptstyle 2$} }$is the \textit{muon} here. The S matrix of this new pde gives the \textit{W and Z as resonances and does not require renormalization counterterms or free parameters. }Thus we get nuclear, weak and E{\&}M phenomenology as\textit{ one} step solutions of this new pde, not requiring the standard method's pathology of adhoc assumptions such as gauges and counterterms, 19 free parameters (you can vary any way you want) that have confused, blocked the progress of theoretical physics for the past 30 years. [Preview Abstract] |
Friday, March 20, 2009 9:48AM - 10:00AM |
Y13.00010: The darkness of mere being: DM and DE explained James Beichler In previous APS meetings, I have presented a geometrical explanation of Dark Matter and Dark Energy that makes testable predictions and is thus completely falsifiable. The theory is based on a macroscopically extended fourth dimension of space that yields a five-dimensional space-time structure. In this structure, the four-dimensional space-time of relativity is extrinsically curved in the higher spatial dimension. Dark Matter is curvature in the higher dimension that is not directly associated with local matter, but instead results from an interaction between local matter or curvature and the global curvature due to all matter in the universe. Criticisms that the theory was not mathematical have now been overcome and a simple algebraic formula that corresponds to the geometry of the four-dimensional structure of space has been derived. The algebraic formula appears to be Newtonian, but it implies a five-dimensional unified field structure such as that developed by Kaluza in 1921 and extended by Einstein and his colleagues in the late 1930s. The new equation also shows how gravity can be quantized on the basis of relativity without hypothesizing the discrete nature of matter, i.e., the existence of specific ``particles'' of gravity, inherent in quantum mechanics, the Standard Model and other quantum models. [Preview Abstract] |
Friday, March 20, 2009 10:00AM - 10:12AM |
Y13.00011: Charged Particles are Preventing from Moving Faster than the Speed of Light by Light Itself Randy Wayne Many problems in classical mechanics are solved by assuming that friction is negligible. At velocities close to the speed of light, however, friction is never negligible as a consequence of the dilatant optical molasses that results from the temperature-dependent blackbody distribution of photons. A body moving at relativistic velocities experiences the blackbody radiation as being Doppler shifted. This adds a nonlinear velocity-dependent component of friction. By accounting for this thermodynamic friction, I have obtained an equation of motion that is applicable for modeling the movement of particles at relativistic velocities. While the predictions of the opto-mechanical model are qualitatively consistent with the predictions of the Theory of Special Relativity in terms of the nonlinear relationship between force and acceleration, there are quantitative and testable differences. [Preview Abstract] |
Friday, March 20, 2009 10:12AM - 10:24AM |
Y13.00012: Why So Many More Americans Die in Fires Lawrence Cranberg ``Why So Many More Americans Die in Fires'' is the headline on Page 3 of The New York Times' full-page story on December 22, l991, by D. G. McNeil, Jr. This is a partial report based on personal experience with domestic fire making for thermal comfort since l975 (1) and a published claim (2) of unique safety benefits.The McNeil report attributes the problem to ``A Case of Bad Attitude'' and ``A Reliance on Technology.'' That implies a ``bad attitude'' on the part of technologists - a conclusion consistent with this technologist's thirty-five years of experience with fellow technologists, who has found ``buck-passing'' the favorite recourse of technologists in the highest places in government even though, as McNeil has written, ``Many children never wake up. Smoke or toxic gases overcome them as they sleep. When fire fighters lift them, their imprints remain.'' Regrettably, in this author's experience, the courts have also displayed a ``bad attitude'' where ``life and death issues'' have been pleaded. 1. L. Cranberg, Slot Flame Stablity with Hohlraum Radiation Pattern, BAPS, Series II, Vol. 20, No. 9, Sept., l978. 2. L. Cranberg, Fireplace Firesafety, Fire Journal, Letter, May/June,l987 [Preview Abstract] |
Friday, March 20, 2009 10:24AM - 10:36AM |
Y13.00013: A new Virtual Crystal Approximation approach Roberta Poloni, Jorge I\~{n}iguez, Alberto Garcia, Enric Canadell It is well known that the virtual crystal approximation (VCA) provides an efficient method for studying disordered alloys and solid solutions by first-principles. Although several studies have reported VCA results regarding stability issues by using energetic considerations, here we propose a new approach based on alternative structural indicators. The reason for this is that it is still not clear whether energy comparisons for different virtual compositions are trustworthy. Our non-fully-predictive scheme makes use of some experimental information in order address structural problems like atomic ordering and/or partial occupation at some site. We look at different figures of merit (energy derivatives), depending on the amount of experimental information taken into account, and we minimize them with respect to different possible structural configurations. By applying our approach to a wide number of well known systems (oxinitrides, borocarbides, perovskites, etc.) we have been able to reproduce the experimental structure in all cases. [Preview Abstract] |
Friday, March 20, 2009 10:36AM - 10:48AM |
Y13.00014: Solvent-Shift Monte Carlo: A cluster algorithm for solvated atomistic and coarse-grained systems David Earl, Christopher Hixson, James Benigni We present a cluster algorithm for the efficient simulation of solvated molecules that we term solvent-shift Monte Carlo (SSMC). The algorithm involves a conformational change in a solvated solute molecule of interest, followed by a geometrical rotation of solvent particles. The method satisfies detailed balance and can be applied to existing schemes to sample conformational space, where an axis or plane of rotation can be defined. We demonstrate that the algorithm significantly enhances the sampling of phase space in solvated systems, and may be easily combined with other advanced sampling techniques such as parallel tempering. [Preview Abstract] |
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