Based on the Wigner function in local equilibrium, we derive hydrodynamical quantities for a system of polarized spin-1/2 particles: the particle number current density, the energy-momentum tensor, the spin tensor, an...Based on the Wigner function in local equilibrium, we derive hydrodynamical quantities for a system of polarized spin-1/2 particles: the particle number current density, the energy-momentum tensor, the spin tensor, and the dipole moment tensor. Compared with ideal hydrodynamics without spin, additional terms at the first and second orders in the Knudsen number Κ_(n) and the average spin polarization Χ_(s) have been derived. The Wigner function can be expressed in terms of matrix-valued distributions, whose equilibrium forms are characterized by thermodynamical parameters in quantum statistics. The equations of motion for these parameters are derived by conservation laws at the leading and next-to-leading order Κ_(n) and Χ_(s).展开更多
We introduce a new interpretation of chemical potential and show that holographic entropy is entropybound,which is supported by two ideal cases discussed in detail.One is sparse but incompressible liquid like a star o...We introduce a new interpretation of chemical potential and show that holographic entropy is entropybound,which is supported by two ideal cases discussed in detail.One is sparse but incompressible liquid like a star ofuniform density and the other is a screen at infinity in spherically symmetric spacetime.Our work is based on the newscenario of entropy force and holographic thermodynamics,and the Brown-York quasi-local energy.展开更多
The unsteady magnetohydrodynamic flow of an electrically conducting viscous incompressible third grade fluid bounded by an infinite porous plate is studied with the Hall effect. An external uniform magnetic field is a...The unsteady magnetohydrodynamic flow of an electrically conducting viscous incompressible third grade fluid bounded by an infinite porous plate is studied with the Hall effect. An external uniform magnetic field is applied perpendicular to the plate and the fluid motion is subjected to a uniform suction and injection. Similarity transformations are employed to reduce the non-linear equations governing the flow under discussion to two ordinary differential equations (with and without dispersion terms). Using the finite difference scheme, numerical solutions represented by graphs with reference to the various involved parameters of interest are discussed and appropriate conclusions are drawn.展开更多
Influences of topological defect and dislocation on conductivity behavior of charge carriers in external electromagnetic fields are studied. Particularly the quantum Hall effect is investigated in detail. It is found ...Influences of topological defect and dislocation on conductivity behavior of charge carriers in external electromagnetic fields are studied. Particularly the quantum Hall effect is investigated in detail. It is found that the nontrivial deformations of spacetime due to topological defect and dislocation produce an electric current at the leading order of perturbation theory. This current then induces a deformation on the Hall conductivity. The corrections on the Hall conductivity depend on the external electric fields, the size of the sample and the momentum of the particle.展开更多
Ultracompact dark matter minihalos (UCMHs) would be formed during the early universe if there were large density perturbations. If dark matter can decay into particles described by the standard model, such as neutri...Ultracompact dark matter minihalos (UCMHs) would be formed during the early universe if there were large density perturbations. If dark matter can decay into particles described by the standard model, such as neutrinos, these objects would become potential astrophysical sources of emission which could be detected by in- struments such as IceCube. In this paper, we investigate neutrino signals from nearby UCMHs due to gravitino dark matter decay and compare these signals with the back- ground neutrino flux which is mainly from the atmosphere to obtain constraints on the abundance of UCMHs.展开更多
Recently,it has been realized that in some systems internal space rotation can induce energy amplification for scattered waves,similar to rotation in real space.In particularly,it has been shown that energy extraction...Recently,it has been realized that in some systems internal space rotation can induce energy amplification for scattered waves,similar to rotation in real space.In particularly,it has been shown that energy extraction is possible for a Q-ball,a stationary non-topological soliton that is coherently rotating in its field space.In this paper,we generalize the analysis to the case of boson stars,and show that the same energy extraction mechanism still works for boson stars.展开更多
We propose a new holographic program of gravity in which we introduce a surface stress tensor.Our proposal differs from Verlinde's in several aspects.First,we use an open or a closed screen.Second,the temperature ...We propose a new holographic program of gravity in which we introduce a surface stress tensor.Our proposal differs from Verlinde's in several aspects.First,we use an open or a closed screen.Second,the temperature is not necessary,but a surface energy density and pressure are introduced.The surface stress tensor is proportional to the extrinsic curvature.Third,the energy we use is Brown-York energy and the equipartition theorem is violated by a non-vanishing surface pressure.We discuss holographic thermodynamics of a gas of weak gravity and find a chemical potential,and then show that Verlinde's program does not lead to reasonable thermodynamics.The holographic entropy is similar to the Bekenstein entropy bound.展开更多
In the strong uniform magnetic field, the noncommutative plane (NCP) caused by the lowest Landau level (LLL) effect, and QED with NCP (QED-NCP) are studied. Being similar to the condensed matter theory of quantu...In the strong uniform magnetic field, the noncommutative plane (NCP) caused by the lowest Landau level (LLL) effect, and QED with NCP (QED-NCP) are studied. Being similar to the condensed matter theory of quantum Hall effect, an effective filling factor f(B) is introduced to characterize the possibility that the electrons stay on the LLL. The analytic and numerical results of the differential cross section for the process of backward Compton scattering in accelerator with unpolarized or polarized initial photons are calculated. The existing data of BL38B2 in Spring-8 have been analyzed roughly and compared with the numerical predictions primitively. We propose a precise measurement of the differential cross sections of backward Compton scattering in a strong perpendicular magnetic field, which may reveal the effects of NCP.展开更多
I show the formulation of de Sitter Special Relativity (dS-SR) based on Dirac-Lu-Zou-Guo’s discussions. dS-SR quantum mechanics is formulated, and the dS-SR Dirac equation for hydrogen is suggested. The equation in...I show the formulation of de Sitter Special Relativity (dS-SR) based on Dirac-Lu-Zou-Guo’s discussions. dS-SR quantum mechanics is formulated, and the dS-SR Dirac equation for hydrogen is suggested. The equation in the earth-QSO framework reference is solved by means of the adiabatic approach. It’s found that the fine-structure "constant" α in dS-SR varies with time. By means of the t-z relation of the ΛCDM model, α’s time-dependency becomes redshift z-dependent. The dS-SR’s predictions of △α/α agree with data of spectra of 143 quasar absorption systems, the dS-space-time symmetry is SO(3, 2) (i.e., anti-dS group) and the universal parameter R (de Sitter ratio) in dS-SR is estimated to be R ≈ 2.73×1012 ly. The effects of dS-SR become visible at the cosmic space-time scale (i.e., the distance 109 ly). At that scale, dS-SR is more reliable than Einstein SR. The α-variation with time is evidence of SR with de Sitter symmetry.展开更多
In recent years there has been a lot of interest in discussing frame depeudences/independences of the cosmological perturbations under the conforlnal transformations. This problem has previously been investigated in L...In recent years there has been a lot of interest in discussing frame depeudences/independences of the cosmological perturbations under the conforlnal transformations. This problem has previously been investigated in Lerlns of the cow^riant approach for a single component universe, and it was found that tile covariant approach is very powerful to pick out the perturbative variables which are both gauge and conformal invariant. In this work, we extend the covariant approach to a universe with multicomponent fluids. We find that similar results can be derived, as e, xpected. In addition, some other interesting perturbations are also identified to be conformal invariant, such as entropy perturbation between two different components.展开更多
Riemannian geometry, as a basis for general relativity, can be obtained from the more general Finsler geometry in terms of the Cartan connection and Chern connection, as discussed frequently in the literature. However...Riemannian geometry, as a basis for general relativity, can be obtained from the more general Finsler geometry in terms of the Cartan connection and Chern connection, as discussed frequently in the literature. However, there are other gravity theories that can be made to be equivalent to general relativity but are based on non-Riemannian geometry. Famous examples are the Teleparallel and Symmetric Teleparallel gravity theories. In this paper, we show how to obtain the geometry for Teleparallel gravity from Finsler geometry in terms of a ‘Teleparallel type’ connection.展开更多
Within the standard model,we have investigated rare Z-boson decays into double heavy quarkonia,Z→VV and Z→VP,with V and P denoting vector and pseudo scalar quarkonia,respectively.It is assumed that the leading-order...Within the standard model,we have investigated rare Z-boson decays into double heavy quarkonia,Z→VV and Z→VP,with V and P denoting vector and pseudo scalar quarkonia,respectively.It is assumed that the leading-order QCD diagrams would give the dominant contributions to these processes,and the corresponding branching fractions,for instance,B(Z→J/ΨJ/Ψ),have been estimated to be approximately 10^(-13)in literature.However,these decays could also happen through electromagnetic transitions Z→Vγ^(*)and Z→Pγ^(*),with the virtual photon transforming into V.Interestingly,the smallness of the vector quarkonium mass can give rise to a large factor m_(Z)^(2)/m_(V)^(2)relative to the QCD contributions,which thus counteracts the suppression from the electromagnetic coupling.We systematically include these two types of contributions in our calculation to predict branching fractions for these decays.Particularly,owing to the virtual photon effects,it is found that B(Z→J/ΨJ/Ψ)will be significantly enhanced,up to 10^(-10).展开更多
Recently BICEP2 collaboration has announced the detection of the primordial gravitational waves at high confidence level.In light of the results of B-modes power spectrum from BICEP2 and using the basedΛCDM,a constra...Recently BICEP2 collaboration has announced the detection of the primordial gravitational waves at high confidence level.In light of the results of B-modes power spectrum from BICEP2 and using the basedΛCDM,a constraint on the tensor-to-scalar ratio r=0.20+0.07-0.05(68%C.L.)can be obtained,however,this result is in apparent tension with the limit on standard inflation models from the recent PLANCK measurement,r<0.11(95%C.L.).Herein we review the recent progress on the cosmological studies after BICEP2 and discuss on different ways of reconciling the tension between PLANCK and BICEP2 data.We will discuss possible modifications on the standard cosmological model,such as including the running of scalar spectral index or other cosmological parameters correlated with inflationary cosmological parameters,or tilting the primordial power spectrum at large scales by introducing a cut off which can be predicted by bouncing cosmology.We will also comment on another possibility of generating extra B-modes of CMB polarization,namely by a non-zero polarization rotation angle during its transferring from the last scattering surface.展开更多
This is a follow of previous work entitled "One Electron Atom in Special Relativity with de Sitter SpaceTime Symmetry" [Commun. Theor. Phys. 57(2012) 930]. In this paper, we consider the higher order calcula...This is a follow of previous work entitled "One Electron Atom in Special Relativity with de Sitter SpaceTime Symmetry" [Commun. Theor. Phys. 57(2012) 930]. In this paper, we consider the higher order calculations and contributions in the previous framework to solve one electron atoms in de Sitter invariant relativistic quantum mechanics. The next-to-leading-order calculations in 1/R2-expansions show that the fine-structure constant α is variant with cosmologic time going by in the de Sitter invariant special relativistic quantum mechanics with standard FRW cosmologic model.展开更多
The de Sitter invariant Special Relativity(dS-SR) is SR with constant curvature,and a natural extension of usual Einstein SR(E-SR).In this paper,we solve the dS-SR Dirac equation of Hydrogen by means of the adiabatic ...The de Sitter invariant Special Relativity(dS-SR) is SR with constant curvature,and a natural extension of usual Einstein SR(E-SR).In this paper,we solve the dS-SR Dirac equation of Hydrogen by means of the adiabatic approach and the quasi-stationary perturbation calculations of QM.Hydrogen atom is located in the light cone of the Universe.FRW metric and ΛCDM cosmological model are used to discuss this issue.To the atom,effects of de Sitter space-time geometry described by Beltrami metric are taken into account.The dS-SR Dirac equation turns out to be a time dependent quantum Hamiltonian system.We reveal that:(i) The fundamental physics constants m e,,e variate adiabatically along with cosmologic time in dS-SR QM framework.But the fine-structure constant α≡ e 2 /(c) keeps to be invariant;(ii)(2s 1/2-2p 1/2)-splitting due to dS-SR QM effects:By means of perturbation theory,that splitting E(z) are calculated analytically,which belongs to O(1/R 2)-physics of dS-SR QM.Numerically,we find that when |R| {10 3 Gly,10 4 Gly,10 5 Gly},and z {1,or 2},the E(z) 1(Lamb shift).This indicates that for these cases the hyperfine structure effects due to QED could be ignored,and the dS-SR fine structure effects are dominant.This effect could be used to determine the universal constant R in dS-SR,and be thought as a new physics beyond E-SR.展开更多
Extending the holographic program of our previous work,we derive f(R) gravity and the Maxwell equations from the holographic principle,using time-like holographic screens.We find that to derive the Einstein equations ...Extending the holographic program of our previous work,we derive f(R) gravity and the Maxwell equations from the holographic principle,using time-like holographic screens.We find that to derive the Einstein equations and f(R) gravity by a natural holographic approach,the quasi-static condition is necessary.We also find the surface stress tensor and the surface electric current,surface magnetic current on a holographic screen for f(R) gravity and Maxwell's theory,respectively.展开更多
We discuss the variation of the fine-structure constant, α. There are obvious discrepancies among the results of α-variation from recent Quasi-stellar observation experiments and from the Oklo uranium mine analysis....We discuss the variation of the fine-structure constant, α. There are obvious discrepancies among the results of α-variation from recent Quasi-stellar observation experiments and from the Oklo uranium mine analysis. We use dS Sitter invariant Special Relativity (SRc,R) and Dirac large number hypothesis to discuss this puzzle, and present a possible solution to the disagreement. By means of the observational data and the discussions presented in this paper, we estimate the radius of the Universe in SRc,R which is about -2√5× 10^11.y.展开更多
基金Supported by the National Natural Science Foundation of China (Grant Nos. 11890713, 11890710, 11947301, 11935007, 11221504,11861131009, 11890714, 11890710, and 12047528)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No. XDB34030102)。
文摘Based on the Wigner function in local equilibrium, we derive hydrodynamical quantities for a system of polarized spin-1/2 particles: the particle number current density, the energy-momentum tensor, the spin tensor, and the dipole moment tensor. Compared with ideal hydrodynamics without spin, additional terms at the first and second orders in the Knudsen number Κ_(n) and the average spin polarization Χ_(s) have been derived. The Wigner function can be expressed in terms of matrix-valued distributions, whose equilibrium forms are characterized by thermodynamical parameters in quantum statistics. The equations of motion for these parameters are derived by conservation laws at the leading and next-to-leading order Κ_(n) and Χ_(s).
基金Supported by the National Natural Science Foundation of China under Grant Nos 10588503, 10535060, and 10975128, the National Basic Research Program of China under Grant No 2007CB815401, and the Pujiang Talent Project of the Shanghai Science and Technology Committee under Grant No 06PJ14114.
文摘We introduce a new interpretation of chemical potential and show that holographic entropy is entropybound,which is supported by two ideal cases discussed in detail.One is sparse but incompressible liquid like a star ofuniform density and the other is a screen at infinity in spherically symmetric spacetime.Our work is based on the newscenario of entropy force and holographic thermodynamics,and the Brown-York quasi-local energy.
文摘The unsteady magnetohydrodynamic flow of an electrically conducting viscous incompressible third grade fluid bounded by an infinite porous plate is studied with the Hall effect. An external uniform magnetic field is applied perpendicular to the plate and the fluid motion is subjected to a uniform suction and injection. Similarity transformations are employed to reduce the non-linear equations governing the flow under discussion to two ordinary differential equations (with and without dispersion terms). Using the finite difference scheme, numerical solutions represented by graphs with reference to the various involved parameters of interest are discussed and appropriate conclusions are drawn.
基金Supported by the China Scholarship Council under Grant No 201207010002the Hanjiang Scholar Project of Shaanxi University of Technology+3 种基金the National Natural Science Foundation of China under Grant No 11147181the Scientific Research Project of Shaanxi Province under Grant Nos 2009K01-54 and 12JK0960the Startup Foundation of the University of Science and Technology of Chinathe Project of Knowledge Innovation Program of the Chinese Academy of Sciences
文摘Influences of topological defect and dislocation on conductivity behavior of charge carriers in external electromagnetic fields are studied. Particularly the quantum Hall effect is investigated in detail. It is found that the nontrivial deformations of spacetime due to topological defect and dislocation produce an electric current at the leading order of perturbation theory. This current then induces a deformation on the Hall conductivity. The corrections on the Hall conductivity depend on the external electric fields, the size of the sample and the momentum of the particle.
基金Supported by the National Natural Science Foundation of China
文摘Ultracompact dark matter minihalos (UCMHs) would be formed during the early universe if there were large density perturbations. If dark matter can decay into particles described by the standard model, such as neutrinos, these objects would become potential astrophysical sources of emission which could be detected by in- struments such as IceCube. In this paper, we investigate neutrino signals from nearby UCMHs due to gravitino dark matter decay and compare these signals with the back- ground neutrino flux which is mainly from the atmosphere to obtain constraints on the abundance of UCMHs.
基金support by the Fundamental Research Funds for the Central Universities(Grant No.WK2030000036)the National Natural Science Foundation of China(Grant Nos.12075233and 12247103)+2 种基金the National Key R&D Program of China(Grant No.2022YFC220010)funded by STFC Consolidated(Grant No.ST/T000732/1)support from the National Natural Science Foundation of China(Grant No.123B1030)。
文摘Recently,it has been realized that in some systems internal space rotation can induce energy amplification for scattered waves,similar to rotation in real space.In particularly,it has been shown that energy extraction is possible for a Q-ball,a stationary non-topological soliton that is coherently rotating in its field space.In this paper,we generalize the analysis to the case of boson stars,and show that the same energy extraction mechanism still works for boson stars.
基金supported by the National Natural Science Foundation of China (Grant Nos.10535060/A050207,10975172 and 10821504)the National Basic Research Program of China (Grant No.2007CB815401)
文摘We propose a new holographic program of gravity in which we introduce a surface stress tensor.Our proposal differs from Verlinde's in several aspects.First,we use an open or a closed screen.Second,the temperature is not necessary,but a surface energy density and pressure are introduced.The surface stress tensor is proportional to the extrinsic curvature.Third,the energy we use is Brown-York energy and the equipartition theorem is violated by a non-vanishing surface pressure.We discuss holographic thermodynamics of a gas of weak gravity and find a chemical potential,and then show that Verlinde's program does not lead to reasonable thermodynamics.The holographic entropy is similar to the Bekenstein entropy bound.
基金National Natural Science Foundation of China(90403021)PhD Program Funds of the Education Ministry of China,Pujiang Talent Project of the Shanghai Science Technology Committee(06PJ14114)Hundred Talents Project of Shanghai Institute of Applied Physics
文摘In the strong uniform magnetic field, the noncommutative plane (NCP) caused by the lowest Landau level (LLL) effect, and QED with NCP (QED-NCP) are studied. Being similar to the condensed matter theory of quantum Hall effect, an effective filling factor f(B) is introduced to characterize the possibility that the electrons stay on the LLL. The analytic and numerical results of the differential cross section for the process of backward Compton scattering in accelerator with unpolarized or polarized initial photons are calculated. The existing data of BL38B2 in Spring-8 have been analyzed roughly and compared with the numerical predictions primitively. We propose a precise measurement of the differential cross sections of backward Compton scattering in a strong perpendicular magnetic field, which may reveal the effects of NCP.
基金Supported by NSF (10975128)973 Program of China (2007CB815401)
文摘I show the formulation of de Sitter Special Relativity (dS-SR) based on Dirac-Lu-Zou-Guo’s discussions. dS-SR quantum mechanics is formulated, and the dS-SR Dirac equation for hydrogen is suggested. The equation in the earth-QSO framework reference is solved by means of the adiabatic approach. It’s found that the fine-structure "constant" α in dS-SR varies with time. By means of the t-z relation of the ΛCDM model, α’s time-dependency becomes redshift z-dependent. The dS-SR’s predictions of △α/α agree with data of spectra of 143 quasar absorption systems, the dS-space-time symmetry is SO(3, 2) (i.e., anti-dS group) and the universal parameter R (de Sitter ratio) in dS-SR is estimated to be R ≈ 2.73×1012 ly. The effects of dS-SR become visible at the cosmic space-time scale (i.e., the distance 109 ly). At that scale, dS-SR is more reliable than Einstein SR. The α-variation with time is evidence of SR with de Sitter symmetry.
文摘In recent years there has been a lot of interest in discussing frame depeudences/independences of the cosmological perturbations under the conforlnal transformations. This problem has previously been investigated in Lerlns of the cow^riant approach for a single component universe, and it was found that tile covariant approach is very powerful to pick out the perturbative variables which are both gauge and conformal invariant. In this work, we extend the covariant approach to a universe with multicomponent fluids. We find that similar results can be derived, as e, xpected. In addition, some other interesting perturbations are also identified to be conformal invariant, such as entropy perturbation between two different components.
基金supported in part by NSFC under Grant No.12075231 and 12047502。
文摘Riemannian geometry, as a basis for general relativity, can be obtained from the more general Finsler geometry in terms of the Cartan connection and Chern connection, as discussed frequently in the literature. However, there are other gravity theories that can be made to be equivalent to general relativity but are based on non-Riemannian geometry. Famous examples are the Teleparallel and Symmetric Teleparallel gravity theories. In this paper, we show how to obtain the geometry for Teleparallel gravity from Finsler geometry in terms of a ‘Teleparallel type’ connection.
基金Supported in part by the National Natural Science Foundation of China(11575175,12047502)National Research and development Program of China(2020YFA0406400)。
文摘Within the standard model,we have investigated rare Z-boson decays into double heavy quarkonia,Z→VV and Z→VP,with V and P denoting vector and pseudo scalar quarkonia,respectively.It is assumed that the leading-order QCD diagrams would give the dominant contributions to these processes,and the corresponding branching fractions,for instance,B(Z→J/ΨJ/Ψ),have been estimated to be approximately 10^(-13)in literature.However,these decays could also happen through electromagnetic transitions Z→Vγ^(*)and Z→Pγ^(*),with the virtual photon transforming into V.Interestingly,the smallness of the vector quarkonium mass can give rise to a large factor m_(Z)^(2)/m_(V)^(2)relative to the QCD contributions,which thus counteracts the suppression from the electromagnetic coupling.We systematically include these two types of contributions in our calculation to predict branching fractions for these decays.Particularly,owing to the virtual photon effects,it is found that B(Z→J/ΨJ/Ψ)will be significantly enhanced,up to 10^(-10).
基金supported by the National Natural Science Foundation of China (Grant Nos. 11033005, 11322325, 11075074, 11121092, 11033005 and 11375202)the National Basic Research Program of China (Grant No. 2010CB83300)+1 种基金the Program for New Century Excellent Talents in Universitythe National Youth Thousand Talents Program and the Strategic Priority Research Program "The Emergence of Cosmological Structures" of the Chinese Academy of Sciences (Grant No. XDB09000000)
文摘Recently BICEP2 collaboration has announced the detection of the primordial gravitational waves at high confidence level.In light of the results of B-modes power spectrum from BICEP2 and using the basedΛCDM,a constraint on the tensor-to-scalar ratio r=0.20+0.07-0.05(68%C.L.)can be obtained,however,this result is in apparent tension with the limit on standard inflation models from the recent PLANCK measurement,r<0.11(95%C.L.).Herein we review the recent progress on the cosmological studies after BICEP2 and discuss on different ways of reconciling the tension between PLANCK and BICEP2 data.We will discuss possible modifications on the standard cosmological model,such as including the running of scalar spectral index or other cosmological parameters correlated with inflationary cosmological parameters,or tilting the primordial power spectrum at large scales by introducing a cut off which can be predicted by bouncing cosmology.We will also comment on another possibility of generating extra B-modes of CMB polarization,namely by a non-zero polarization rotation angle during its transferring from the last scattering surface.
基金Acknowledgements This research was supported by the National Natural Science Foundation of China (Grant Nos. 10535060/A050207, 10975172, and 10821504) and Ministry of Science and Technology 973 Program under grant No. 2007CB815401. Yi Wang acknowledges support from grants from Kavli IPMU, McGill University, the Institute of Particle Physics (Canada) and the Foundational Questions Institute.
基金Supported in part by National Natural Science Foundation of China under Grant No.11375169
文摘This is a follow of previous work entitled "One Electron Atom in Special Relativity with de Sitter SpaceTime Symmetry" [Commun. Theor. Phys. 57(2012) 930]. In this paper, we consider the higher order calculations and contributions in the previous framework to solve one electron atoms in de Sitter invariant relativistic quantum mechanics. The next-to-leading-order calculations in 1/R2-expansions show that the fine-structure constant α is variant with cosmologic time going by in the de Sitter invariant special relativistic quantum mechanics with standard FRW cosmologic model.
基金Supported in part by National Natural Science Foundation of China under Grant No. 10975128by the Chinese Science Academy Foundation under Grant No. KJCX-YW-N29
文摘The de Sitter invariant Special Relativity(dS-SR) is SR with constant curvature,and a natural extension of usual Einstein SR(E-SR).In this paper,we solve the dS-SR Dirac equation of Hydrogen by means of the adiabatic approach and the quasi-stationary perturbation calculations of QM.Hydrogen atom is located in the light cone of the Universe.FRW metric and ΛCDM cosmological model are used to discuss this issue.To the atom,effects of de Sitter space-time geometry described by Beltrami metric are taken into account.The dS-SR Dirac equation turns out to be a time dependent quantum Hamiltonian system.We reveal that:(i) The fundamental physics constants m e,,e variate adiabatically along with cosmologic time in dS-SR QM framework.But the fine-structure constant α≡ e 2 /(c) keeps to be invariant;(ii)(2s 1/2-2p 1/2)-splitting due to dS-SR QM effects:By means of perturbation theory,that splitting E(z) are calculated analytically,which belongs to O(1/R 2)-physics of dS-SR QM.Numerically,we find that when |R| {10 3 Gly,10 4 Gly,10 5 Gly},and z {1,or 2},the E(z) 1(Lamb shift).This indicates that for these cases the hyperfine structure effects due to QED could be ignored,and the dS-SR fine structure effects are dominant.This effect could be used to determine the universal constant R in dS-SR,and be thought as a new physics beyond E-SR.
基金supported by the National Natural Science Foundation ofChina (Grant Nos. 10535060,A050207,10975172 and 10821504)the National Basic Research Program of China (Grant No. 2007CB815401)
文摘Extending the holographic program of our previous work,we derive f(R) gravity and the Maxwell equations from the holographic principle,using time-like holographic screens.We find that to derive the Einstein equations and f(R) gravity by a natural holographic approach,the quasi-static condition is necessary.We also find the surface stress tensor and the surface electric current,surface magnetic current on a holographic screen for f(R) gravity and Maxwell's theory,respectively.
基金National Natural Science Foundation of China (90403021)PhD Program Funds of Education Ministry ofChina (20020358040)
文摘We discuss the variation of the fine-structure constant, α. There are obvious discrepancies among the results of α-variation from recent Quasi-stellar observation experiments and from the Oklo uranium mine analysis. We use dS Sitter invariant Special Relativity (SRc,R) and Dirac large number hypothesis to discuss this puzzle, and present a possible solution to the disagreement. By means of the observational data and the discussions presented in this paper, we estimate the radius of the Universe in SRc,R which is about -2√5× 10^11.y.