期刊文献+
共找到1,696篇文章
< 1 2 85 >
每页显示 20 50 100
The Perihelion Precession of the Planets Indicates a Variability of the Gravitational Constant
1
作者 Hans Peter Weber 《Journal of Modern Physics》 CAS 2023年第5期670-675,共6页
The gravitational constant G according to the theory of NEWTON is the most imprecise constant of all physical constants. Moreover, there are a number of phenomena which suggest that this is caused by its invariant nat... The gravitational constant G according to the theory of NEWTON is the most imprecise constant of all physical constants. Moreover, there are a number of phenomena which suggest that this is caused by its invariant nature and the gravitation constant might be in fact a variable. In this article, a possible dependence of the gravitational constant on the distance between the two mass points is determined from the observed values of the perihelion displacement of the planets. However, to fit the observed measurements the 1/r<sup>2</sup> dependence is modified to a 1/r2+1/R</sup> dependence with “R” as the Rydberg constant. With the proposed new power function, the perihelion precessions of the planets are recalculated and then compared with previous observations as well as the postulated anomaly of Saturn. 展开更多
关键词 gravitational constant Perihelion Precession of the Planets gravitational Equation with variable G
下载PDF
Variable Physical Constants and Beyond
2
作者 Qinghua Cui 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2023年第1期116-123,共8页
We previously revealed that the speed of light in vacuum c, the gravitational constant G, the vacuum permittivity ε, and the vacuum permeability μ can be defined by the temperature T (or the expected average frequen... We previously revealed that the speed of light in vacuum c, the gravitational constant G, the vacuum permittivity ε, and the vacuum permeability μ can be defined by the temperature T (or the expected average frequency f) of cosmic microwave background (CMB) radiation. Given that CMB is continuously cooling, that is, T is continuously decreasing, we proposed that the above “constants” are variable and their values at some space-time with CMB temperature T (c<sub>T</sub>, G<sub>T</sub>, ε<sub>T</sub>, and μ<sub>T</sub>) can be described using their values (c<sub>0</sub>, G<sub>0</sub>, ε<sub>0</sub>, and μ<sub>0</sub>) and the temperature (T<sub>0</sub>) of CMB at present space-time. Based on the above observation, a number of physical equations related with these constants are re-described in this study, including relativity equation, mass-energy equation, and Maxwell’s equations, etc. 展开更多
关键词 Speed of Light in Vacuum gravitational constant Vacuum Permittivity Vacuum Permeability Cosmic Microwave Background
下载PDF
Not Relying on the Newton Gravitational Constant Gives More Accurate Gravitational Predictions
3
作者 Espen Gaarder Haug 《Journal of Applied Mathematics and Physics》 2023年第10期3124-3158,共35页
The Newton gravitational constant is considered a cornerstone of modern gravity theory. Newton did not invent or use the gravity constant;it was invented in 1873, about the same time as it became standard to use the k... The Newton gravitational constant is considered a cornerstone of modern gravity theory. Newton did not invent or use the gravity constant;it was invented in 1873, about the same time as it became standard to use the kilogram mass definition. We will claim that G is just a term needed to correct the incomplete kilogram definition so to be able to make gravity predictions. But there is another way;namely, to directly use a more complete mass definition, something that in recent years has been introduced as collision-time and a corresponding energy called collision-length. The collision-length is quantum gravitational energy. We will clearly demonstrate that by working with mass and energy based on these new concepts, rather than kilogram and the gravitational constant, one can significantly reduce the uncertainty in most gravity predictions. 展开更多
关键词 gravity Predictions Reduction of Errors Newton’s gravitational constant Collision Space-Time Cavendish Apparatus Planck Length Planck Time
下载PDF
Explanation of the Necessity of the Empirical Equations That Relate the Gravitational Constant and the Temperature of the CMB
4
作者 Tomofumi Miyashita 《Journal of Modern Physics》 CAS 2023年第4期432-444,共13页
In previous papers, we proposed an empirical equation for the fine-structure constant. Using this equation, we proposed a refined version of our own former empirical equations about the electromagnetic force and gravi... In previous papers, we proposed an empirical equation for the fine-structure constant. Using this equation, we proposed a refined version of our own former empirical equations about the electromagnetic force and gravity in terms of the temperature of the cosmic microwave background. The calculated values of the temperature of the cosmic microwave background (T<sub>c</sub>) and the gravitational constant (G) were 2.726312 K and 6.673778 × 10<sup>-11</sup> m<sup>3</sup>⋅kg<sup>-1</sup>⋅ s<sup>-2</sup>, respectively. Then, for the values of the factors 9/2 and π in our equations, we used 4.488519503 and 3.132011447, respectively. However, we could not provide a theoretical explanation for the necessity of these empirical equations. In this paper, using the redefinition method for the UNIT, we show the necessity for our empirical equations. 展开更多
关键词 gravitational constant Temperature of the Cosmic Microwave Background
下载PDF
Relativistic Supernova Blast Waves Exhibit Properties of Gravitational Lenses and the Hubble Constant
5
作者 Paul Marko 《Journal of High Energy Physics, Gravitation and Cosmology》 2023年第4期1237-1258,共22页
Simulations based on Supernova (SN) observations predict several galactic SN explosions (SNe) can occur every century. Unlike SNes within the Interstellar Medium (ISM) where ambient gas generally absorbs blast waves w... Simulations based on Supernova (SN) observations predict several galactic SN explosions (SNe) can occur every century. Unlike SNes within the Interstellar Medium (ISM) where ambient gas generally absorbs blast waves within a million years, SNes occurring in a rarified environment outside of the ISM generate blast waves which remain in a relativistic free expansion phase for more extended periods. The SN blast wave forms an expanding spherical shell and when multiple blast waves intersect, the overlapping region naturally takes the form of a ring, an arc, or an Einstein Cross structure. The analysis shows the relativistic plasma establishes a medium with permeability which drives the index of refraction greater than 1. As a result, when a shock discontinuity forms in the overlapping region, light is reflected from the host galaxy which exposes the intersecting blast wave regions. The expanding shells are shown to induce an achromatic redshift to the reflected light consistent with those measured for gravitational lenses. Further, it is shown that a Hubble equation for a blast wave around the Milky Way Galaxy can be parameterized to approximate measured redshifts over a wide range of distances. 展开更多
关键词 SUPERNOVA PLASMA gravitational Lens Einstein Cross Hubble constant
下载PDF
Precise Measurements of the Gravitational Constant: Revaluation by the Information Approach 被引量:2
6
作者 Boris Menin 《Journal of Applied Mathematics and Physics》 2019年第6期1272-1288,共17页
The gravitational constant discovered by Newton is still measured with a relative uncertainty that is several orders of magnitude larger than the relative uncertainty of other fundamental constants. Numerous methods a... The gravitational constant discovered by Newton is still measured with a relative uncertainty that is several orders of magnitude larger than the relative uncertainty of other fundamental constants. Numerous methods are used to measure it. This article discusses the information-oriented approach for analyzing the achievable relative measurement uncertainty, in which the magnitude of the gravitational constant can be considered as plausible. A comparison is made and the advantages and disadvantages of various methods are discussed in terms of the possibility of achieving higher accuracy using a new metric called comparative uncertainty, which was proposed by Brillouin. 展开更多
关键词 gravitational constant COMPARATIVE UNCERTAINTY INFORMATION Theory Modeling RELATIVE UNCERTAINTY
下载PDF
Adiabaticity Violated Not Enough: Presume Primordial Black Holes to Generate Gravitons for Cosmological Constant, as Candidate for DE Initially
7
作者 Andrew Walcott Beckwith 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2023年第1期100-107,共8页
Instant preheating as given in terms of window where adiabaticity is violated is a completely inefficient form of particle production if we use Padmandabhan scalar potentials. This necessitates using a very different ... Instant preheating as given in terms of window where adiabaticity is violated is a completely inefficient form of particle production if we use Padmandabhan scalar potentials. This necessitates using a very different mechanism for early universe gravition production as an example which is to break up the initial “mass” formed about 10<sup>60</sup> times Planck mass into graviton emitting 10<sup>5</sup> gram sized micro black holes. The mechanism is to assume that we have a different condition than the usual adiabaticity idea which is connected with reheating of the universe. Hence, we will be looking at an earlier primordial black hole generation for generation of gravitons. 展开更多
关键词 Black Holes Cosmological constant Universe gravition
下载PDF
Time Varying Gravitational Constant G via Entropic Force 被引量:1
8
作者 M.R.Setare D.Momeni 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第10期691-694,共4页
If the uncertainty principle applies to the Verlinde entropic idea, it leads to a new term in the Newton's second law of mechanics in the Planck's scale. This curious velocity dependent term inspires a frictional fe... If the uncertainty principle applies to the Verlinde entropic idea, it leads to a new term in the Newton's second law of mechanics in the Planck's scale. This curious velocity dependent term inspires a frictional feature of the gravity. In this short letter we address that this new term modifies the effective mass and the Newtonian constant as the time dependent quantities. Thus we must have a running on the value of the effective mass on the particle mass m near the holographic screen and the G. This result has a nigh relation with the Dirac hypothesis about the large numbers hypothesis (L.N.H.). We propose that the corrected entropie terms via Verlinde idea can be brought as a holographic evidence for the authenticity of the Dirac idea. 展开更多
关键词 gravitational constant general relativing
下载PDF
Is Quintessence an Indication of a Time-Varying Gravitational Constant? 被引量:1
9
作者 Christopher Pilot 《Journal of High Energy Physics, Gravitation and Cosmology》 2019年第1期41-81,共41页
A model is presented where the quintessence parameter, w, is related to a time-varying gravitational constant. Assuming a present value of w = -0.98 , we predict a current variation of ?/G = -0.06H0, a value within cu... A model is presented where the quintessence parameter, w, is related to a time-varying gravitational constant. Assuming a present value of w = -0.98 , we predict a current variation of ?/G = -0.06H0, a value within current observational bounds. H0 is Hubble’s parameter, G is Newton’s constant and ? is the derivative of G with respect to time. Thus, G has a cosmic origin, is decreasing with respect to cosmological time, and is proportional to H0, as originally proposed by the Dirac-Jordan hypothesis, albeit at a much slower rate. Within our model, we can explain the cosmological constant fine-tuning problem, the discrepancy between the present very weak value of the cosmological constant, and the much greater vacuum energy found in earlier epochs (we assume a connection exists). To formalize and solidify our model, we give two distinct parametrizations of G with respect to “a”, the cosmic scale parameter. We treat G-1 as an order parameter, which vanishes at high energies;at low temperatures, it reaches a saturation value, a value we are close to today. Our first parametrization for G-1 is motivated by a charging capacitor;the second treats G-1(a) by analogy to a magnetic response, i.e., as a Langevin function. Both parametrizations, even though very distinct, give a remarkably similar tracking behavior for w(a) , but not of the conventional form, w(a) = w0 + wa(1-a) , which can be thought of as only holding over a limited range in “a”. Interestingly, both parametrizations indicate the onset of G formation at a temperature of approximately 7×1021 degrees Kelvin, in contrast to the ΛCDM model where G is taken as a constant all the way back to the Planck temperature, 1.42×1032 degrees Kelvin. At the temperature of formation, we find that G has increased to roughly 4×1020 times its current value. For most of cosmic evolution, however, our variable G model gives results similar to the predictions of the ΛCDM model, except in the very early universe, as we shall demonstrate. In fact, in the limit where w approaches -1, the expression, ?/G , vanishes, and we are left with the concordance model. Within our framework, the emergence of dark energy over matter at a scale of a ≈ 0.5 is that point where G-1 increases noticeably to its current value, G0-1 . This weakening of G to its current value G0 is speculated as the true cause for the observed unanticipated acceleration of the universe. 展开更多
关键词 TIME-VARYING gravitational constant COSMOLOGICAL constant QUINTESSENCE Dark Energy
下载PDF
QED-Like Simple High Order Perturbative Relation between the Gravitational Constant <i>G</i>and the Planck Constant <i>h</i> 被引量:1
10
作者 Matt Kalinski 《Journal of High Energy Physics, Gravitation and Cosmology》 2021年第2期595-601,共7页
We find a simple precise formula for the gravitational constant <i>G</i> relating it to the electron charge, electron mass, the vacuum dielectric constant and the speed of light (or magnetic permeability o... We find a simple precise formula for the gravitational constant <i>G</i> relating it to the electron charge, electron mass, the vacuum dielectric constant and the speed of light (or magnetic permeability of the vacuum) in power of the fine structure constant <i>i.e.</i> relating the gravitational constant to the Planck constant through others which also well exist without the quantum mechanics therefore relating two fundamental constants as not independent through the parameters of the electron and the electromagnetic properties of the vacuum. 展开更多
关键词 gravitational constant Planck constant Quantum gravity Theory of Everything Theory of the Electron Structure
下载PDF
On maximum power point tracking control strategy for variable speed constant frequency wind power generation 被引量:1
11
作者 倪红军 《Journal of Chongqing University》 CAS 2010年第1期21-28,共8页
Based on the characteristic of AC-excited variable speed constant frequency(VSCF)wind power generation,the vector control technique was applied in a doubly fed induction generator(DFIG).Maximum wind energy or maximum ... Based on the characteristic of AC-excited variable speed constant frequency(VSCF)wind power generation,the vector control technique was applied in a doubly fed induction generator(DFIG).Maximum wind energy or maximum output power point can be tracked by decoupling control of active power and reactive power.The research result shows that the net power of generation system delivered to grid in maximum wind energy tracking mode is not the most.We presented a novel maximum power point tracking(MPPT)control strategy by analyzing the DFIG mathematic model and power relations which delivered the maximum power to the grid.The maximum power point could be tracked automatically without measuring wind speed in the control strategy and the control was independent of optimal turbine power curve,which had excellent dynamic and static performances and robustness.Simulation and experimental results testify the accuracy and validity of the control strategy. 展开更多
关键词 variable speed constant frequency grid voltage orientation DECOUPLING maximum power point tracking
下载PDF
Quantum Gravitational Energy Simplifies Gravitational Physics and Gives a New Einstein Inspired Quantum Field Equation without G
12
作者 Espen Gaarder Haug 《Journal of High Energy Physics, Gravitation and Cosmology》 2023年第3期626-653,共28页
We show the simplest form with which one can express the gravity force, and that still gives all the same predictions of observable phenomena as does standard Newton gravity and general relativity theory. In addition,... We show the simplest form with which one can express the gravity force, and that still gives all the same predictions of observable phenomena as does standard Newton gravity and general relativity theory. In addition, we show a new field equation that gives all the same predictions as general relativity theory, but that it is simpler as the only constant needed is the speed of light and that also gives quantum gravity. This new form to express gravity, through quantum gravitational energy, requires less constants to predict gravity phenomena than standard gravity theory. This alone should make the physics community interested in investigating this approach. It shows that gravitational energy, and other types of energy are a collision-length in their most complete and deepest form and that quantization of gravity is related to the reduced Compton frequency of the gravitational mass per Planck time. While general relativity theory needs two constants to predict gravity phenomena, that is G and c, our new theory, based on gravity energy, only needs one constant, c<sub>g</sub>, that is easily found from gravitational observations with no prior knowledge of any constants. Further, we will show that, at the deepest quantum level, quantum gravity needs two constants, c<sub>g</sub> and the Planck length, while the standard formulation here needs c, h and l<sub>p</sub>. Thus our theory gives a reduction in constants and simpler formulas than does standard gravity theory. Most important we by this seems to have a fully consistent framework for quantum gravity. 展开更多
关键词 Quantum gravity gravity Force Newton gravity General Relativity Theory gravitational Energy gravity constant
下载PDF
The Life Predictions in Whole Process Realized with Different Variables and Conventional Materials Constants for Elastic-Plastic Materials Behaviors under Unsymmetrical Cycle Loading 被引量:1
13
作者 Yangui Yu 《Journal of Mechanics Engineering and Automation》 2015年第4期241-250,共10页
Author researches a lot of the mathematical models and the related conventional material constants in the traditional and the modem mechanics; to adopt two types of variables a and D, for the fatigue-damage-fracture b... Author researches a lot of the mathematical models and the related conventional material constants in the traditional and the modem mechanics; to adopt two types of variables a and D, for the fatigue-damage-fracture behaviors to elastic-plastic steels contained flaws, to put forward several calculation models, which are the driving force and the life prediction expressions at each stage and in whole process; for the key parameters .A1 and ,A2 in two stages, there are functional relation with other conventional material constants σF,m1 and M2,λ2, they are defined as the new calculable comprehensive material constants, and indicate their physical and geometrical meanings. In addition, for conversion methods between two types of variables, relevant calculating example is provided. Thereby, make a linking between the fracture mechanics and the damage mechanics, communicating their relationships. This works for saving man powers and funds on fatigue-damage-fracture testing that will be having practical significance. 展开更多
关键词 Life in whole process variables of two types driving force elastic-plastic materials conventional material constants.
下载PDF
Newton Did Not Invent or Use the So-Called Newton’s Gravitational Constant;G, It Has Mainly Caused Confusion 被引量:1
14
作者 Espen Gaarder Haug 《Journal of Modern Physics》 2022年第2期179-205,共27页
Newton did not invent or use the so-called Newton’s gravitational constant G. Newton’s original gravity formula was and not . In this paper, we will show how a series of major gravity phenomena can be calculated and... Newton did not invent or use the so-called Newton’s gravitational constant G. Newton’s original gravity formula was and not . In this paper, we will show how a series of major gravity phenomena can be calculated and predicted without the gravitational constant. This is, to some degree, well known, at least for those that have studied a significant amount of the older literature on gravity. However, to understand gravity at a deeper level, still without G, one needs to trust Newton’s formula. It is when we first combine Newton’s assumptionn, that matter and light ultimately consist of hard indivisible particles, with new insight in atomism that we can truly begin to understand gravity at a deeper level. This leads to a quantum gravity theory that is unified with quantum mechanics and in which there is no need for G and not even a need for the Planck constant. We claim that two mistakes have been made in physics, which have held back progress towards a unified quantum gravity theory. First, it has been common practice to consider Newton’s gravitational constant as almost holy and untouchable. Thus, we have neglected to see an important aspect of mass;namely, the indivisible particle that Newton also held in high regard. Second, standard physics have built their quantum mechanics around the de Broglie wavelength, rather than the Compton wavelength. We claim the de Broglie wavelength is merely a mathematical derivative of the Compton wavelength, the true matter wavelength. 展开更多
关键词 Newton gravity Newton’s gravitational constant Schwarzschild Radius Quantum gravity Planck Length
下载PDF
On the Cosmic Evolution of the Quantum Vacuum Using Two Variable G Models and Winterberg’s Thesis
15
作者 Christopher Pilot 《Journal of High Energy Physics, Gravitation and Cosmology》 2023年第4期1134-1160,共27页
We work within a Winterberg framework where space, i.e., the vacuum, consists of a two component superfluid/super-solid made up of a vast assembly (sea) of positive and negative mass Planck particles, called planckion... We work within a Winterberg framework where space, i.e., the vacuum, consists of a two component superfluid/super-solid made up of a vast assembly (sea) of positive and negative mass Planck particles, called planckions. These material particles interact indirectly, and have very strong restoring forces keeping them a finite distance apart from each other within their respective species. Because of their mass compensating effect, the vacuum appears massless, charge-less, without pressure, net energy density or entropy. In addition, we consider two varying G models, where G, is Newton’s constant, and G<sup>-1</sup>, increases with an increase in cosmological time. We argue that there are at least two competing models for the quantum vacuum within such a framework. The first follows a strict extension of Winterberg’s model. This leads to nonsensible results, if G increases, going back in cosmological time, as the length scale inherent in such a model will not scale properly. The second model introduces a different length scale, which does scale properly, but keeps the mass of the Planck particle as, ± the Planck mass. Moreover we establish a connection between ordinary matter, dark matter, and dark energy, where all three mass densities within the Friedman equation must be interpreted as residual vacuum energies, which only surface, once aggregate matter has formed, at relatively low CMB temperatures. The symmetry of the vacuum will be shown to be broken, because of the different scaling laws, beginning with the formation of elementary particles. Much like waves on an ocean where positive and negative planckion mass densities effectively cancel each other out and form a zero vacuum energy density/zero vacuum pressure surface, these positive mass densities are very small perturbations (anomalies) about the mean. This greatly alleviates, i.e., minimizes the cosmological constant problem, a long standing problem associated with the vacuum. 展开更多
关键词 Winterberg Model Planck Particles Positive and Negative Mass Planck Particles Planckions Quantum Vacuum Space as a Superfluid/Supersolid Extended Models for Space Cosmological constant Higgs Field as a Composite Particle Higgs Boson Inherent Length Scale for the Vacuum Dark Energy Cosmological Scaling Behavior for the Quantum Vacuum variable G Models Extended gravity Newton’s constant as an Order Parameter High Energy Behavior for the Vacuum
下载PDF
Concept study of measuring gravitational constant using superconducting gravity gradiometer
16
作者 Xing Bian Ho Jung Paik Martin Vol Moody 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第8期130-135,共6页
Newton's gravitational constant G is the least known fundamental constant of nature. Since Cavendish made the first measurement of G with a torsion balance over two hundred years ago, the best results of G have been ... Newton's gravitational constant G is the least known fundamental constant of nature. Since Cavendish made the first measurement of G with a torsion balance over two hundred years ago, the best results of G have been obtained by using torsion balances. However, the uncorrected anelasticity of torsion fibers makes the results questionable. We present a new method of G measurement by using a superconducting gravity gradiometer constructed with levitated test masses, which is free from the irregularities of mechanical suspension. The superconducting gravity gradiometer is rotated to generate a centrifugal acceleration that nulls the gravity field of the source mass, forming an artificial planetary system. This experiment has a potential accuracy of G better than 10 ppm. 展开更多
关键词 gravitational constant superconducting gravity gradiometer artificial planetary system
下载PDF
A Short Discussion on the Gravitational Redshift in the Light of an Alleged Local Variability of the Planck Constant
17
作者 Carmine Cataldo 《Journal of Applied Mathematics and Physics》 2017年第5期1001-1008,共8页
The aim of this paper fundamentally lies in proposing an alternative explanation to the so-called gravitational redshift. The above-mentioned phenomenon, experimentally verified more than half a century ago, is common... The aim of this paper fundamentally lies in proposing an alternative explanation to the so-called gravitational redshift. The above-mentioned phenomenon, experimentally verified more than half a century ago, is commonly legitimised by means of Special Relativity. In our case, since time is considered as being absolute, we simply postulate a local variability of the Plank constant. Ultimately, we carry out an alternative deduction of the relation that expresses the gravitational redshift as a function of a parameter that, in our case, does not coincide with a Schwarzschild coordinate. 展开更多
关键词 gravitational REDSHIFT variable PLANCK constant ABSOLUTENESS of Time
下载PDF
Bulk Viscous Anisotropic Cosmological Models with Generalized Chaplygin Gas with Time Varying Gravitational and Cosmological Constants
18
作者 Shubha Kotambkar Gyan Prakash Singh Rupali Kelkar 《Natural Science》 2015年第6期312-323,共12页
This paper is devoted to studying the generalized Chaplygin gas models in Bianchi type III space- time geometry with time varying bulk viscosity, cosmological and gravitational constants. We are considering the condit... This paper is devoted to studying the generalized Chaplygin gas models in Bianchi type III space- time geometry with time varying bulk viscosity, cosmological and gravitational constants. We are considering the condition on metric potential . Also to obtain deterministic models we have considered physically reasonable relations like , and the equation of state for generalized Chaplygin gas given by . A new set of exact solutions of Einstein’s field equations has been obtained in Eckart theory, truncated theory and full causal theory. Physical behaviour of the models has been discussed. 展开更多
关键词 Bianchi Type III BULK VISCOSITY COSMOLOGICAL constant gravitational constant Generalized Chaplygin Gas
下载PDF
Bianchi Type-V Cosmological Models for Perfect Fluid with Time-Varying Gravitational and Cosmological Constant
19
作者 Mohammed Aman Ullah Mohammad Amjad Hossain Mohammad Moksud Alam 《Journal of Applied Mathematics and Physics》 2017年第11期2283-2290,共8页
Einstein’s field equations with variable gravitational and cosmological constants are considered in presence of perfect fluid for locally-rotationally-symmetric (LRS) Bianchi type-V space-time discussion in context o... Einstein’s field equations with variable gravitational and cosmological constants are considered in presence of perfect fluid for locally-rotationally-symmetric (LRS) Bianchi type-V space-time discussion in context of the particle creation. We present new shear free solutions for both absence and presence of particle creation. The solution describes the particle and entropy generation in the anisotropic cosmological models. We observe that time variation of gravitational and cosmological constant is needed for particle creation phenomena. Moreover, we obtained the particle production rate Γ(t) for this model and discussed in detail. 展开更多
关键词 LRS Bianchi Type-V Perfect Fluid gravitational constant COSMOLOGICAL constant Particle Creation
下载PDF
The Sum and Difference of Two Constant Elasticity of Variance Stochastic Variables
20
作者 Chi-Fai Lo 《Applied Mathematics》 2013年第11期1503-1511,共9页
We have applied the Lie-Trotter operator splitting method to model the dynamics of both the sum and difference of two correlated constant elasticity of variance (CEV) stochastic variables. Within the Lie-Trotter split... We have applied the Lie-Trotter operator splitting method to model the dynamics of both the sum and difference of two correlated constant elasticity of variance (CEV) stochastic variables. Within the Lie-Trotter splitting approximation, both the sum and difference are shown to follow a shifted CEV stochastic process, and approximate probability distributions are determined in closed form. Illustrative numerical examples are presented to demonstrate the validity and accuracy of these approximate distributions. These approximate probability distributions can be used to valuate two-asset options, e.g. spread options and basket options, where the CEV variables represent the forward prices of the underlying assets. Moreover, we believe that this new approach can be extended to study the algebraic sum of N CEV variables with potential applications in pricing multi-asset options. 展开更多
关键词 constant ELASTICITY of Variance Stochastic variables Probability Distribution Functions BACKWARD KOLMOGOROV Equation Lie-Trotter Splitting Approximation
下载PDF
上一页 1 2 85 下一页 到第
使用帮助 返回顶部