On a fundamental physical principle underlying the point location algorithm in computer graphics [for EM field theory]

1999 ◽  
Vol 42 (3) ◽  
pp. 200-204 ◽  
Author(s):  
S. Ghosh
Keyword(s):  
Field Theory ◽  
Computer Graphics ◽  
Physical Principle ◽  
Point Location ◽  
Em Field ◽  
Location Algorithm ◽  
Fundamental Physical

scholarly journals Quantum computation of scattering in scalar quantum field theories

2014 ◽  
Vol 14 (11&12) ◽  
pp. 1014-1080 ◽  
Author(s):  
Stephen P. Jordan ◽  
Keith S. M. Lee ◽  
John Preskill
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Strong Coupling ◽  
Interaction Strength ◽  
Quantum Algorithm ◽  
Quantum Field Theories ◽  
Quantum Field ◽  
Scalar Quantum ◽  
Relativistic Scattering ◽  
Fundamental Physical

Quantum field theory provides the framework for the most fundamental physical theories to be confirmed experimentally and has enabled predictions of unprecedented precision. However, calculations of physical observables often require great computational complexity and can generally be performed only when the interaction strength is weak. A full understanding of the foundations and rich consequences of quantum field theory remains an outstanding challenge. We develop a quantum algorithm to compute relativistic scattering amplitudes in massive $\phi^4$ theory in spacetime of four and fewer dimensions. The algorithm runs in a time that is polynomial in the number of particles, their energy, and the desired precision, and applies at both weak and strong coupling. Thus, it offers exponential speedup over existing classical methods at high precision or strong coupling.

Removal of water‐layer multiples from multicomponent sea‐bottom data

Geophysics ◽  
1999 ◽  
Vol 64 (3) ◽  
pp. 838-851 ◽  
Author(s):  
Are Osen ◽  
Lasse Amundsen ◽  
Arne Reitan
Keyword(s):  
Vertical Velocity ◽  
Water Layer ◽  
Real Data ◽  
Physical Principle ◽  
Sea Floor ◽  
Numerical Tests ◽  
Sea Bottom ◽  
Marine Source ◽  
Suppression Technique ◽  
Fundamental Physical

A method for suppressing water‐layer multiples in multicomponent sea‐floor measurements is presented. The multiple suppression technique utilizes the concept of wavefield separation into upgoing and downgoing modes just below the sea floor for eliminating the sea‐floor ghost, the sea‐surface ghost, and the accompanying water‐layer reverberations. The theory applies to each of the recorded components: pressure, vertical velocity, and horizontal velocities. The fundamental physical principle for the multiple suppression technique rests on identifying these multiples as downgoing waves just below the sea floor, while the primaries of interest arriving from the subsurface are upgoing waves. White presented this realization for the pressure component three decades ago; hence, the theory for the velocity field is an extension of the theory. In this paper, the theory is derived for an experiment with a marine source in the water layer above a locally flat, elastic sea floor with known elastic parameters. The method is otherwise multidimensional and operates on a shot‐to‐shot basis; hence, it is computationally fast. Aside from this, we show that this demultiple method removes the strongest multiples in sea‐floor data without knowledge of the source wavelet. Synthetic and real data examples are provided to illustrate the application of the algorithms to the pressure, in‐line velocity, and vertical velocity components. The numerical tests show that strong multiples have been attenuated on the pressure and the velocity recordings, producing promising results.

MESOSCOPIC FIELD THEORY OF IONIC SYSTEMS

2005 ◽  
Vol 19 (21) ◽  
pp. 3309-3343 ◽  
Author(s):  
A. CIACH ◽  
G. STELL
Keyword(s):  
Field Theory ◽  
Short Range ◽  
Tricritical Point ◽  
Universality Class ◽  
Point Location ◽  
Generic Models ◽  
Quantitative Level ◽  
Ionic Systems ◽  
Simulation Results ◽  
Good Agreement

A mesoscopic field theory for the primitive model of ionic systems with additional, short-range interactions is presented. Generic models in continuum space and with positions of the ions restricted to lattice sites of various lattices are described in detail. We describe briefly the field-theoretic methods and review the foundations of the mesoscopic description. The types of phase diagrams predicted by our theory for different versions of the model are presented and discussed. They all agree with recent simulations. On the quantitative level our theory yields an RPM tricritical-point location on the sc lattice which is in good agreement with the simulation results. Arguments indicating that the critical point in the RPM belongs to the Ising universality class are given.

Quantum Field Theory of Dynamics of Spectroscopic Transitions by Strong Dipole-Photon and Dipole-Phonon Coupling

ISRN Optics ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-10
Author(s):  
Alla Dovlatova ◽  
Dmitri Yerchuck
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Optical Systems ◽  
Field Energy ◽  
Quantum Field ◽  
Phonon Coupling ◽  
Emission Process ◽  
Spin Resonance ◽  
Em Field ◽  
Strong Dipole

Matrix-operator difference-differential equations for dynamics of spectroscopic transitions in 1D multiqubit exchange-coupled (para)magnetic and optical systems by strong dipole-photon and dipole-phonon coupling are derived within the framework of quantum field theory. It has been established that by strong dipole-photon and dipole-phonon coupling the formation of long-lived coherent system of the resonance phonons takes place, and relaxation processes acquire pure quantum character. It is determined by the appearance of coherent emission process of EM-field energy, for which the resonance phonon system is responsible. Emission process is accompanied by phonon Rabi quantum oscillation, which can be time-shared from photon quantum Rabi oscillations, accompanying coherent absorption process of EM-field energy. For the case of radio spectroscopy, it corresponds to the possibility of the simultaneous observation along with (para)magntic spin resonance, the acoustic spin resonance.

scholarly journals Field theory in normal conical coordinates

2021 ◽  
Vol 244 ◽  
pp. 09004
Author(s):  
Dmitry Nesnov
Keyword(s):  
Field Theory ◽  
Vector Field ◽  
Computer Graphics ◽  
Vector Fields ◽  
Complex Structure ◽  
Curvilinear Coordinates ◽  
Mathematical Apparatus ◽  
Spherical Coordinate ◽  
Geometrical Modeling ◽  
Scalar And Vector Fields

In the scientific literature, the field theory is most fully covered in the cylindrical and spherical coordinate systems. This is explained by the fact that the mathematical apparatus of these systems is most well studied. When the source of field has a more complex structure than a point or a straight line, there is a need for new approaches to their study. The goal of this research is to adapt the field theory related to curvilinear coordinates in order to represent it in the normal conical coordinates. In addition, an important part of the research is the development of a geometrical modeling apparatus for scalar and vector field level surfaces using computer graphics. The paper shows the dependences of normal conical coordinates on rectangular Cartesian coordinates, Lame coefficients. The differential characteristics of the scalar and vector fields in normal conical coordinates are obtained: Laplacian of scalar and vector fields, divergence, rotation of the vector field. The example case shows the features of the application of the mathematical apparatus of geometrical field modeling in normal conical coordinates. For the first time, expressions for the characteristics of the scalar and vector fields in normal conical coordinates are obtained. Methods for geometrical modeling of fields using computer graphics have been developed to provide illustration in their study.

scholarly journals The Electromagnetic Will

NeuroSci ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 291-304
Author(s):  
Johnjoe McFadden
Keyword(s):  
Field Theory ◽  
Free Will ◽  
Conscious Mind ◽  
Em Field ◽  
The Brain ◽  
Ephaptic Coupling

The conscious electromagnetic information (cemi) field theory proposes that the seat of consciousness is the brain’s electromagnetic (EM) field that integrates information from trillions of firing neurons. What we call free will is its output. The cemi theory also proposes that the brain has two streams. Most actions are initiated by the first non-conscious stream that is composed of neurons that are insulated from EM field influences. These non-conscious involuntary actions are thereby invisible to our EM field-located thoughts. The theory also proposes that voluntary actions are driven by neurons that receive EM field inputs and are thereby visible to our EM field-located thoughts. I review the extensive evidence for EM field/ephaptic coupling between neurons and the increasing evidence that EM fields in the brain are a cause of behaviour. I conclude by arguing that though this EM field-driven will is not free, in the sense of being acausal, it nevertheless corresponds to the very real experience of our conscious mind being in control of our voluntary actions. Will is not an illusion. It is our experience of control by our EM field-located mind. It is an immaterial, yet physical, will.

scholarly journals Field theory in normal toroidal coordinates

2018 ◽  
Vol 193 ◽  
pp. 03022
Author(s):  
Dmitry V. Nesnov
Keyword(s):  
Field Theory ◽  
Vector Field ◽  
Computer Graphics ◽  
Geometric Modeling ◽  
Vector Fields ◽  
Scientific Paper ◽  
Curvilinear Coordinates ◽  
Coordinate Systems ◽  
Scalar And Vector Fields ◽  
Toroidal Coordinates

Field theory is widely represented in spherical and cylindrical coordinate systems, since the mathematical apparatus of these coordinate systems has been thoroughly studied. Sources of field with more complex structures require new approaches to their study. The purpose of this research is to adapt the field theory referred to curvilinear coordinates and represent it in normal toroidal coordinates. Another purpose is to develop the foundations of geometric modeling with the use of computer graphics for visualizing the level surfaces. The dependence of normal toroidal coordinates on rectangular Cartesian coordinates and Lame coefficients is shown in this scientific paper. Differential characteristics of scalar and vector fields in normal toroidal coordinates are obtained: scalar and vector field laplacians, divergence, and rotation of vector field. The example shows the technique of modeling the field and its further computer visualization. The technique of reading the internal equation of the surface is presented and the influence of the values of the parameters on the shape of the surface is shown. For the first time, expressions of scalar and vector field characteristics in normal toroidal coordinates are obtained, the fundamentals of geometric modeling of fields with the use of computer graphics tools are developed for the purpose of providing visibility for their study.

About the Point Location Problem

2010 ◽  
pp. 100-105
Author(s):  
José Poveda ◽  
Michael Gould
Keyword(s):  
Location Problem ◽  
Computational Cost ◽  
Point Location ◽  
Location Algorithm

In this chapter we present some well-known algorithms for the solution of the point location problem and for the more particular problem of point-in-polygon determination. These previous approaches to the problem are presented in the first sections. In the remainder of the paper, we present a quick location algorithm based on a quaternary partition of the space, as well as its associated computational cost.

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