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Restrictions on negative energy density for the Dirac field in flat spacetime
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作者 舒维星 余洪伟 +2 位作者 李飞 吴普训 任中洲 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第5期934-939,共6页
This paper investigates the quantum Dirac field in n + 1-dimensional flat spacetime and derives a lower bound in the form of quantum inequality on the energy density averaged against spacetime sampling functions. The... This paper investigates the quantum Dirac field in n + 1-dimensional flat spacetime and derives a lower bound in the form of quantum inequality on the energy density averaged against spacetime sampling functions. The stateindependent quantum inequality derived in the present paper is similar to the temporal quantum energy inequality and it is stronger for massive field than for massless one. It also presents the concrete results of the quantum inequality in 2 and 4-dimensional spacetimes. 展开更多
关键词 negative energy density quantum inequality spacetime averaged
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The Strange Relationship between the Momentum of a Photon Emitted from an Electron and the Momentum Acquired by the Electron
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作者 Koshun Suto 《Journal of Applied Mathematics and Physics》 2024年第7期2652-2664,共13页
In quantum mechanics, the energy of a hydrogen atom is minimized when the principal quantum number n is 1. However, the author has previously pointed out that the hydrogen atom has a state where n=0. An electron in th... In quantum mechanics, the energy of a hydrogen atom is minimized when the principal quantum number n is 1. However, the author has previously pointed out that the hydrogen atom has a state where n=0. An electron in the state where n=0has zero rest mass energy. However, a hydrogen atom has an energy level even lower than the n=0state. This is hard to accept from the standpoint of common sense. Thus, the author has previously pointed out that an electron at the energy level where n=0has zero energy because the positive energy mec2and negative energy −mec2cancel each other out. This paper elucidates the strange relationship between the momentum of a photon emitted when a hydrogen atom is formed by an electron with such characteristics, and the momentum acquired by the electron. 展开更多
关键词 Einstein’s energy-Momentum Relationship energy-Momentum Relationship in a Hydrogen Atom Momentum of a Photon Momentum of a Electron negative energy Specific to the Electron Dark Matter
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Regression analysis and features of negative activation energy for MHD nanofluid flow model:A comparative study
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作者 B.Kumara Prachi +3 位作者 Abhinav Singhal R.Nandkeolyar Pulkit Kumar Ali J.Chamkha 《Propulsion and Power Research》 SCIE 2023年第2期273-283,共11页
This article elucidates the impact of activation energy on magnetohydrodynamic(MHD)stagnation point nanofluid flow over a slippery surface in a porous regime with thermophoretic and Brownian diffusions.Negative activa... This article elucidates the impact of activation energy on magnetohydrodynamic(MHD)stagnation point nanofluid flow over a slippery surface in a porous regime with thermophoretic and Brownian diffusions.Negative activation energy is scarce in practice,but the impact of negative activation energy could not be neglected as it is noticed in chemical processes.The rate of some Arrhenius-compliant reactions is retarded by increasing the temperature and is therefore associated with negative activation energies,such as exothermic binding of urea or water.In some processes,the temperature dependence of the pressure-induced unfolding and the urea-induced unfolding of proteins at ambient pressure give negative activation energies.The present mathematical model is solved with successive linearization method(a spectral technique).A comparison of results is made for negative and positive values of activation energy.Apart from it,the quadratic multiple regression model is discussed briefly and explained with bar diagrams.It is observed that with rise in unsteadiness parameter from 0 to 1(taking positive activation energy),skin friction and Sherwood number are increased by 9.36%and 19%respectively,and Nusselt number is decreased by 26%.However,for negative activation energy,9.36%and 112%enhancement is observed in skin friction and Sherwood number,respectively. 展开更多
关键词 negative activation energy Regression analysis Successive linearization method Porous medium
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Quantum Inequality Bounds for Free Rarita-Schwinger Field in Flat Spacetime
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作者 SHU Wei-Xing YU Hong-Wei +2 位作者 LI Fei WU Pu-Xun REN Zhong-Zhou 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第1X期87-90,共4页
Although quantum field theory allows the local energy density negative, it also places severe restrictions on the negative energy. One of the restrictions is the quantum energy inequality (QEI), in which the energy ... Although quantum field theory allows the local energy density negative, it also places severe restrictions on the negative energy. One of the restrictions is the quantum energy inequality (QEI), in which the energy density is averaged over time, or space, or over space and time. By now temporal QEIs have been established for various quantum fields, but less work has been done for the spacetime quantum energy inequality. In this paper we deal with the free Rarita-Schwinger field and present a quantum inequality bound on the energy density averaged over space and time. Comparison with the QEI for the Rarita-Schwinger field shows that the lower bound is the same with the QEI. At the same time, we find the quantum inequality for the Rarita-Schwinger field is weaker than those for the scalar and Dirac fields. This fact gives further support to the conjecture that the more freedom the field has, the more easily the field displays negative energy density and the weaker the quantum inequality becomes. 展开更多
关键词 negative energy density quantum inequality
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Metabolic Disorders of Transitional Low Production Dairy Cow
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作者 C. Promkot J. Mansathit M. Wanapat 《Journal of Agricultural Science and Technology(A)》 2011年第8期1221-1223,共3页
The objective of this study was to assess the occurrence of metabolic disorders in periparturient low milk production (〈 15 kg/d) dairy cows. Data were collected between April 2009 and April 2010 from randomly sele... The objective of this study was to assess the occurrence of metabolic disorders in periparturient low milk production (〈 15 kg/d) dairy cows. Data were collected between April 2009 and April 2010 from randomly selected Holstein crossed breed dairy cow and heifer (30 cows ',and 10 heifers) on faculty farm of faculty of Natural Resources Rajamangala University of Technology Isan, Skon-nakon Campus. Blood samples were collected weekly from each cow, starting 2 weeks before expected calving until 4 weeks postpartum. Serum was analyzed for NEFA and BHBA. The critical threshold for [NEFA] was defined as: 〉 0.4 mmol/L when 〈 -7 to 0 DIM, and 〉 0.7 mmol/L when 3 DIM. Postpartum sub-clinical ketosis (SK) was defined using [BHBA] 〉 14.4 mg/dl. The prevalence of elevated NEFA was 82.5%, 27.5%, 27.5% 7.5% and 7.5% in the dry period, 1st, 2nd 3rd and 5th weeks of lactation, respectively. The prevalence of SK was 12.5% at 2nd weeks of lactation. High prevalence of elevated NEFA during dry period through first 2 weeks of postpartum indicated that periparturient dairy cows suffered some degree of negative energy balance (NEB). These resulted indicated that though, milk yield of these cows were not that high, NEB and ketosis are still major nutrient-related problems. 展开更多
关键词 Metabolic disease negative energy balance NEFA and BHBA.
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A Reformulation of Newton Second Law for Charged Particles and Its Application to Quantum Dynamics
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作者 Vu B. Ho 《Journal of Applied Mathematics and Physics》 2021年第11期2796-2806,共11页
We propose a reformulation of Newton’s second law of motion for charged particles and possible applications of the reformulation to quantum dynamics. We show that the negative energy states arising from the Dirac equ... We propose a reformulation of Newton’s second law of motion for charged particles and possible applications of the reformulation to quantum dynamics. We show that the negative energy states arising from the Dirac equation in relativistic quantum mechanics can be verified using the reformulating framework. We also discuss possible hidden dynamics underlying the concept of quantum jumps in quantum mechanics as outlined in Schr<span style="font-size:12px;white-space:nowrap;">&#246;</span>dinger’s article: ARE THERE QUANTUM JUMPS? In this case, we show that the hidden dynamics of quantum jumps are also determined by the Coulomb interaction between charged particles. 展开更多
关键词 Reformulation of Newton Second Law Dirac negative energy States Quantum Jumps in Quantum Mechanics
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Rotating Squeezed Vacua as Time Machines
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作者 S. Al Saleh L. A. Al Asfar A. Mahroussah 《Journal of Modern Physics》 2016年第3期304-311,共8页
Squeezed quantum vacua seems to violate the averaged null energy conditions (ANEC’s), because they have a negative energy density. When treated as a perfect fluid, rapidly rotating Casimir plates will create vorticit... Squeezed quantum vacua seems to violate the averaged null energy conditions (ANEC’s), because they have a negative energy density. When treated as a perfect fluid, rapidly rotating Casimir plates will create vorticity in the vacuum bounded by them. The geometry resulting from an arbitrarily extended Casimir plates along their axis of rotation is similar to van Stockum spacetime. We observe closed timelike curves (CTC’s) forming in the exterior of the system resulting from frame dragging. The exterior geometry of this system is similar to Kerr geometry, but because of violation of ANEC, the Cauchy horizon lies outside the system unlike Kerr blackholes, giving more emphasis on whether spacetime is multiply connected at the microscopic level. 展开更多
关键词 Squeezed quantum vacua seems to violate the averaged null energy conditions (ANEC’s) because they have a negative energy density. When treated as a perfect fluid rapidly rotating Casimir plates will create vorticity in the vacuum bounded by them. The geometry resulting from an arbitrarily extended Casimir plates along their axis of rotation is similar to van Stockum spacetime. We observe closed timelike curves (CTC’s) forming in the exterior of the system resulting from frame dragging. The exterior geometry of this system is similar to Kerr geometry but because of violation of ANEC the Cauchy horizon lies outside the system unlike Kerr blackholes giving more emphasis on whether spacetime is multiply connected at the microscopic level.
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Dark Matter Creation and Anti-Gravity Acceleration of the Expanding Universe 被引量:1
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作者 F. C. Hoh 《Journal of Modern Physics》 2021年第3期139-160,共22页
Dark matter is identified as negative relative energy between quarks in proton and is generated in cold hydrogen gas with pressure gradient in gravitational field. Positive relative energy PRE can be generated between... Dark matter is identified as negative relative energy between quarks in proton and is generated in cold hydrogen gas with pressure gradient in gravitational field. Positive relative energy PRE can be generated between quarks in protons in cold hydrogen gas in outskirts of the universe. The mechanisms for such creation of dark matter and PRE are reviewed and updated in greater detail and clearer manner. The so-generated dark matter in a galaxy can account for the galaxy’s rotation curve. Star formation in this galaxy uses up the hydrogen atoms and thereby reduces its dark matter content. Dark matter created in intergalactic hydrogen gas can form filaments. In a hypothetical model of the universe, a hydrogen atom with a small amount of negative relative energy or dark matter at the outskirts of this universe can via collisions with other atoms turn into one with a small positive relative energy PRE. Once such a sign change takes place, gravitational attraction switches to anti-gravity repulsion unopposed by any pressure gradient. This leads to a “run away” hydrogen atom moving away from the mass center of the universe and provides a basic mechanism for the accelerating expansion of the universe. This theoretical expansion and the measured redshift data are both compatible with the conception of an acceleratingly expanding universe and complement each other. But they cannot verify each other directly because the present model has been constructed for purposes different from those of the measurements. But it can be shown that both approaches do support each other qualitatively under certain circumstances for small velocities. Dark matter and PRE in the present model are not foreign objects like WIMPs and dark energy-cosmological constant but can only be created in cold hydrogen gas in gravitational field. To achieve this, infrequent collisions among the hydrogen atoms must take place. Dark matter was created first and can eventually later evolve into PRE in the outskirts of the universe and in the intergalactic void. Dark matter and PRE will disappear if the hydrogen atom carrying them becomes ionized as in stars. 展开更多
关键词 Relative energy between Quarks Scalar Strong Interaction Hadron Theory SSI negative Relative energy Dark Matter Positive Relative energy PRE Anti-Gravity Repulsion Universe Expansion Proton Orbit Hubble’s Law
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On blow-up criterion for the nonlinear Schrodinger equation systems
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作者 Yili GAO 《Frontiers of Mathematics in China》 CSCD 2023年第6期441-447,共7页
In this paper,we study the blow-up problem of nonlinear Schrodinger equations{i■_(t)v+△u+(|u|^(2)+|v|^(2))u=0,(t,x)∈R^(1+n),i■_(t)v+△u+(|u|^(2)+|v|^(2))u=0,(t,x)∈R^(1+n),u(0,x)=u_(0)(x),v(0,x)=v0(x),and prove th... In this paper,we study the blow-up problem of nonlinear Schrodinger equations{i■_(t)v+△u+(|u|^(2)+|v|^(2))u=0,(t,x)∈R^(1+n),i■_(t)v+△u+(|u|^(2)+|v|^(2))u=0,(t,x)∈R^(1+n),u(0,x)=u_(0)(x),v(0,x)=v0(x),and prove that the solution of negative energy(E(u,v)<O)blows up in finite or infinite time. 展开更多
关键词 Nonlinear Schrodinger equations blow up negative energy
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A Krein quantization approach to Klein paradox
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作者 Farrin Payandeh Toradj Mohammad Pur +1 位作者 Mohsen Fathi Zahra Gh.Moghaddam 《Chinese Physics C》 SCIE CAS CSCD 2013年第11期14-19,共6页
In this paper we first introduce the famous Klein tization approach and taking the negative modes into account densities could be achieved without confronting any paradox. paradox. Afterwards by proposing the Krein qu... In this paper we first introduce the famous Klein tization approach and taking the negative modes into account densities could be achieved without confronting any paradox. paradox. Afterwards by proposing the Krein quan- , we will show that the expected and exact current 展开更多
关键词 Klein paradox negative energies Krein quantization
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