The Experts below are selected from a list of 162 Experts worldwide ranked by ideXlab platform
A. F. Santos - One of the best experts on this subject based on the ideXlab platform.
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casimir effect and stefan boltzmann Law at finite temperature in a friedmann robertson walker universe
arXiv: High Energy Physics - Theory, 2020Co-Authors: A. F. Santos, S. C. Ulhoa, F C KhannaAbstract:A spatially flat Friedmann-Robertson-Walker background with a general scale factor is considered. In this space-time, the energy-momentum tensor of the scalar field with a general curvature coupling parameter is obtained. Using the Thermo Field Dynamics (TFD) formalism the Stefan-Boltzmann Law and the Casimir effect at finite temperature are calculated. The Casimir effect at zero temperature is also considered. The expansion of the universe changes these effects. A discussion of these modifications is presented.
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Standard Model Extension and Casimir effect for fermions at finite temperature
Physics Letters B, 2016Co-Authors: A. F. Santos, Faqir C. KhannaAbstract:Abstract Lorentz and CPT symmetries are foundations for important processes in particle physics. Recent studies in Standard Model Extension (SME) at high energy indicate that these symmetries may be violated. Modifications in the lagrangian are necessary to achieve a hermitian hamiltonian. The fermion sector of the standard model extension is used to calculate the effects of the Lorentz and CPT violation on the Casimir effect at zero and finite temperature. The Casimir effect and Stefan–Boltzmann Law at finite temperature are calculated using the thermo field dynamics formalism.
Marin Soljacic - One of the best experts on this subject based on the ideXlab platform.
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near field thermal radiation transfer controlled by plasmons in graphene
Physical Review B, 2012Co-Authors: Ognjen Ilic, Marinko Jablan, John D Joannopoulos, Ivan Celanovic, Hrvoje Buljan, Marin SoljacicAbstract:It is shown that thermally excited plasmon-polariton modes can strongly mediate, enhance, and tune the near-field radiation transfer between two closely separated graphene sheets. The dependence of near-field heat exchange on doping and electron relaxation time is analyzed in the near infrared within the framework of fluctuational electrodynamics. The dominant contribution to heat transfer can be controlled to arise from either interband or intraband processes. We predict maximum transfer at low doping and for plasmons in two graphene sheets in resonance, with orders-of-magnitude enhancement (e.g., ${10}^{2}$ to ${10}^{3}$ for separations between 0.1 $\ensuremath{\mu}\text{m}$ and 10 nm) over the Stefan-Boltzmann Law, known as the far-field limit. Strong, tunable, near-field transfer offers the promise of an externally controllable thermal switch as well as a novel hybrid graphene-graphene thermoelectric/thermophotovoltaic energy conversion platform.
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near field thermal radiation transfer controlled by plasmons in graphene
APS, 2012Co-Authors: Ognjen Ilic, Marinko Jablan, John D Joannopoulos, Ivan Celanovic, Hrvoje Buljan, Marin SoljacicAbstract:It is shown that thermally excited plasmon- polariton modes can strongly mediate, enhance, and tune the near-field radiation transfer between two closely separated graphene sheets. The dependence of near-field heat exchange on doping and electron relaxation time is analyzed in the near infrared within the framework of fluctuational electrodynamics. The dominant contribution to heat transfer can be controlled to arise from either interband or intraband processes. We predict maximum transfer at low doping and for plasmons in two graphene sheets in resonance, with orders-of- magnitude enhancement (e.g., 10^2 to 10^3 for separations between 0.1 μm and 10 nm) over the Stefan-Boltzmann Law, known as the far-field limit. Strong, tunable, near-field transfer offers the promise of an externally controllable thermal switch as well as a novel hybrid graphene- graphene thermoelectric/thermophotovoltaic energy conversion platform.
Faqir C. Khanna - One of the best experts on this subject based on the ideXlab platform.
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Standard Model Extension and Casimir effect for fermions at finite temperature
Physics Letters B, 2016Co-Authors: A. F. Santos, Faqir C. KhannaAbstract:Abstract Lorentz and CPT symmetries are foundations for important processes in particle physics. Recent studies in Standard Model Extension (SME) at high energy indicate that these symmetries may be violated. Modifications in the lagrangian are necessary to achieve a hermitian hamiltonian. The fermion sector of the standard model extension is used to calculate the effects of the Lorentz and CPT violation on the Casimir effect at zero and finite temperature. The Casimir effect and Stefan–Boltzmann Law at finite temperature are calculated using the thermo field dynamics formalism.
Ognjen Ilic - One of the best experts on this subject based on the ideXlab platform.
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near field thermal radiation transfer controlled by plasmons in graphene
Physical Review B, 2012Co-Authors: Ognjen Ilic, Marinko Jablan, John D Joannopoulos, Ivan Celanovic, Hrvoje Buljan, Marin SoljacicAbstract:It is shown that thermally excited plasmon-polariton modes can strongly mediate, enhance, and tune the near-field radiation transfer between two closely separated graphene sheets. The dependence of near-field heat exchange on doping and electron relaxation time is analyzed in the near infrared within the framework of fluctuational electrodynamics. The dominant contribution to heat transfer can be controlled to arise from either interband or intraband processes. We predict maximum transfer at low doping and for plasmons in two graphene sheets in resonance, with orders-of-magnitude enhancement (e.g., ${10}^{2}$ to ${10}^{3}$ for separations between 0.1 $\ensuremath{\mu}\text{m}$ and 10 nm) over the Stefan-Boltzmann Law, known as the far-field limit. Strong, tunable, near-field transfer offers the promise of an externally controllable thermal switch as well as a novel hybrid graphene-graphene thermoelectric/thermophotovoltaic energy conversion platform.
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near field thermal radiation transfer controlled by plasmons in graphene
APS, 2012Co-Authors: Ognjen Ilic, Marinko Jablan, John D Joannopoulos, Ivan Celanovic, Hrvoje Buljan, Marin SoljacicAbstract:It is shown that thermally excited plasmon- polariton modes can strongly mediate, enhance, and tune the near-field radiation transfer between two closely separated graphene sheets. The dependence of near-field heat exchange on doping and electron relaxation time is analyzed in the near infrared within the framework of fluctuational electrodynamics. The dominant contribution to heat transfer can be controlled to arise from either interband or intraband processes. We predict maximum transfer at low doping and for plasmons in two graphene sheets in resonance, with orders-of- magnitude enhancement (e.g., 10^2 to 10^3 for separations between 0.1 μm and 10 nm) over the Stefan-Boltzmann Law, known as the far-field limit. Strong, tunable, near-field transfer offers the promise of an externally controllable thermal switch as well as a novel hybrid graphene- graphene thermoelectric/thermophotovoltaic energy conversion platform.
Khanna, Faqir C. - One of the best experts on this subject based on the ideXlab platform.
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Non-Abelian Gravitoelectromagnetism and applications at finite temperature
2020Co-Authors: Santos A. F., Ramos J., Khanna, Faqir C.Abstract:Studies about a formal analogy between the gravitational and the electromagnetic fields lead to the notion of Gravitoelectromagnetism (GEM) to describe gravitation. In fact, the GEM equations correspond to the weak field approximation of gravitation field. Here a non-abelian extension of the GEM theory is considered. Using the Thermo Field Dynamics (TFD) formalism to introduce temperature effects some interesting physical phenomena are investigated. The non-abelian GEM Stefan-Boltzmann Law and the Casimir effect at zero and finite temperature for this non-abelian field are calculated.Comment: 14 pages, accepted for publication in Advances in High Energy Physic
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On Stefan-Boltzmann Law and the Casimir effect at finite temperature in the Schwarzschild spacetime
'World Scientific Pub Co Pte Lt', 2020Co-Authors: Santos A. F., Ulhoa S. C., Khanna, Faqir C.Abstract:This paper deals with quantum field theory in curved space-time using the Thermo Field Dynamics. The scalar field is coupled to the Schwarzschild space time and then thermalised. The Stefan-Boltzmann Law is established at finite temperature and the entropy of the field is calculated. Then the Casimir energy and pressure are obtained at zero and finite temperature.Comment: 13 pages, accepted for publication in IJMP
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Casimir effect and Stefan-Boltzmann Law at finite temperature in a Friedmann-Robertson-Walker universe
'World Scientific Pub Co Pte Lt', 2020Co-Authors: Santos A. F., Ulhoa S. C., Khanna, Faqir C.Abstract:A spatially flat Friedmann-Robertson-Walker background with a general scale factor is considered. In this space-time, the energy-momentum tensor of the scalar field with a general curvature coupling parameter is obtained. Using the Thermo Field Dynamics (TFD) formalism the Stefan-Boltzmann Law and the Casimir effect at finite temperature are calculated. The Casimir effect at zero temperature is also considered. The expansion of the universe changes these effects. A discussion of these modifications is presented.Comment: 14 pages, accepted for publication in IJMP
