The Experts below are selected from a list of 64116 Experts worldwide ranked by ideXlab platform
A Lopezortega - One of the best experts on this subject based on the ideXlab platform.
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area spectrum of the d dimensional reissner nordstrom black hole in the small charge limit
2011Co-Authors: A LopezortegaAbstract:A conjecture by Hod states that for the black hole horizon the spacing of its area spectrum is determined by the Asymptotic Value of its quasinormal frequencies. Recently to overcome some difficulties, Maggiore proposes some changes to the original Hod's conjecture. Taking into account the modifications proposed by Maggiore we calculate the area quantum of the d-dimensional Reissner–Nordstrom black hole in the small charge limit.
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area spectrum of the d dimensional reissner nordstrom black hole in the small charge limit
2010Co-Authors: A LopezortegaAbstract:A conjecture by Hod states that for the black hole horizon the spacing of its area spectrum is determined by the Asymptotic Value of its quasinormal frequencies. Recently to overcome some difficulties, Maggiore proposes some changes to the original Hod's conjecture. Taking into account the modifications proposed by Maggiore we calculate the area spectrum of the d-dimensional Reissner-Nordstrom black hole in the small charge limit.
Yury Polyanskiy - One of the best experts on this subject based on the ideXlab platform.
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a lower bound on the expected distortion of joint source channel coding
2020Co-Authors: Yuval Kochman, Or Ordentlich, Yury PolyanskiyAbstract:We consider the classic joint source-channel coding problem of transmitting a memoryless source over a memoryless channel. The focus of this work is on the long-standing open problem of finding the rate of convergence of the smallest attainable expected distortion to its Asymptotic Value, as a function of the blocklength $n$ . Our main result is that in general the convergence rate is not faster than $n^{-1/2}$ . In particular, we show that for the problem of transmitting i.i.d uniform bits over a binary symmetric channels with Hamming distortion, the smallest attainable distortion (bit error rate) is at least $\Omega (n^{-1/2})$ above the Asymptotic Value, if the “bandwidth expansion ratio” is above 1.
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a lower bound on the expected distortion of joint source channel coding
2019Co-Authors: Yuval Kochman, Or Ordentlich, Yury PolyanskiyAbstract:We consider the classic joint source-channel coding problem of transmitting a memoryless source over a memoryless channel. The focus of this work is on the rate of convergence of the smallest attainable expected distortion to its Asymptotic Value, as a function of blocklength n. Our main result is that in general the convergence rate is not faster than n−1/2. In particular, we show that for the problem of transmitting i.i.d uniform bits over a binary symmetric channels with Hamming distortion, the smallest attainable distortion (bit error rate) is at least Ω(n−1/2) above the Asymptotic Value, if the "bandwidth expansion ratio" is above 1.
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a lower bound on the expected distortion of joint source channel coding
2019Co-Authors: Yuval Kochman, Or Ordentlich, Yury PolyanskiyAbstract:We consider the classic joint source-channel coding problem of transmitting a memoryless source over a memoryless channel. The focus of this work is on the long-standing open problem of finding the rate of convergence of the smallest attainable expected distortion to its Asymptotic Value, as a function of blocklength $n$. Our main result is that in general the convergence rate is not faster than $n^{-1/2}$. In particular, we show that for the problem of transmitting i.i.d uniform bits over a binary symmetric channels with Hamming distortion, the smallest attainable distortion (bit error rate) is at least $\Omega(n^{-1/2})$ above the Asymptotic Value, if the ``bandwidth expansion ratio'' is above $1$.
J Casoli - One of the best experts on this subject based on the ideXlab platform.
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saturated torque formula for planetary migration in viscous disks with thermal diffusion recipe for protoplanet population synthesis
2010Co-Authors: F Masset, J CasoliAbstract:We provide torque formulae for low-mass planets undergoing type I migration in gaseous disks. These torque formulae put special emphasis on the horseshoe drag, which is prone to saturation: the Asymptotic Value reached by the horseshoe drag depends on a balance between coorbital dynamics (which tends to cancel out or saturate the torque) and diffusive processes (which tend to restore the unperturbed disk profiles, thereby desaturating the torque). We entertain the question of this Asymptotic Value and derive torque formulae that give the total torque as a function of the disk's viscosity and thermal diffusivity. The horseshoe drag features two components: one that scales with the vortensity gradient and another that scales with the entropy gradient and constitutes the most promising candidate for halting inward type I migration. Our analysis, which is complemented by numerical simulations, recovers characteristics already noted by numericists, namely, that the viscous timescale across the horseshoe region must be shorter than the libration time in order to avoid saturation and that, provided this condition is satisfied, the entropy-related part of the horseshoe drag remains large if the thermal timescale is shorter than the libration time. Side results include a study of the Lindblad torque as a function of thermal diffusivity and a contribution to the corotation torque arising from vortensity viscously created at the contact discontinuities that appear at the horseshoe separatrices. For the convenience of the reader mostly interested in the torque formulae, Section 8 is self-contained.
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saturated torque formula for planetary migration in viscous disks with thermal diffusion recipe for protoplanet population synthesis
2010Co-Authors: F Masset, J CasoliAbstract:We provide torque formulae for low mass planets undergoing type I migration in gaseous disks. These torque formulae put special emphasis on the horseshoe drag, which is prone to saturation: the Asymptotic Value reached by the horseshoe drag depends on a balance between coorbital dynamics (which tends to cancel out or saturate the torque) and diffusive processes (which tend to restore the unperturbed disk profiles, thereby desaturating the torque). We entertain here the question of this Asymptotic Value, and we derive torque formulae which give the total torque as a function of the disk's viscosity and thermal diffusivity. The horseshoe drag features two components: one which scales with the vortensity gradient, and one which scales with the entropy gradient, and which constitutes the most promising candidate for halting inward type I migration. Our analysis, which is complemented by numerical simulations, recovers characteristics already noted by numericists, namely that the viscous timescale across the horseshoe region must be shorter than the libration time in order to avoid saturation, and that, provided this condition is satisfied, the entropy related part of the horseshoe drag remains large if the thermal timescale is shorter than the libration time. Side results include a study of the Lindblad torque as a function of thermal diffusivity, and a contribution to the corotation torque arising from vortensity viscously created at the contact discontinuities that appear at the horseshoe separatrices. For the convenience of the reader mostly interested in the torque formulae, section 8 is self-contained.
Yuval Kochman - One of the best experts on this subject based on the ideXlab platform.
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a lower bound on the expected distortion of joint source channel coding
2020Co-Authors: Yuval Kochman, Or Ordentlich, Yury PolyanskiyAbstract:We consider the classic joint source-channel coding problem of transmitting a memoryless source over a memoryless channel. The focus of this work is on the long-standing open problem of finding the rate of convergence of the smallest attainable expected distortion to its Asymptotic Value, as a function of the blocklength $n$ . Our main result is that in general the convergence rate is not faster than $n^{-1/2}$ . In particular, we show that for the problem of transmitting i.i.d uniform bits over a binary symmetric channels with Hamming distortion, the smallest attainable distortion (bit error rate) is at least $\Omega (n^{-1/2})$ above the Asymptotic Value, if the “bandwidth expansion ratio” is above 1.
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a lower bound on the expected distortion of joint source channel coding
2019Co-Authors: Yuval Kochman, Or Ordentlich, Yury PolyanskiyAbstract:We consider the classic joint source-channel coding problem of transmitting a memoryless source over a memoryless channel. The focus of this work is on the rate of convergence of the smallest attainable expected distortion to its Asymptotic Value, as a function of blocklength n. Our main result is that in general the convergence rate is not faster than n−1/2. In particular, we show that for the problem of transmitting i.i.d uniform bits over a binary symmetric channels with Hamming distortion, the smallest attainable distortion (bit error rate) is at least Ω(n−1/2) above the Asymptotic Value, if the "bandwidth expansion ratio" is above 1.
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a lower bound on the expected distortion of joint source channel coding
2019Co-Authors: Yuval Kochman, Or Ordentlich, Yury PolyanskiyAbstract:We consider the classic joint source-channel coding problem of transmitting a memoryless source over a memoryless channel. The focus of this work is on the long-standing open problem of finding the rate of convergence of the smallest attainable expected distortion to its Asymptotic Value, as a function of blocklength $n$. Our main result is that in general the convergence rate is not faster than $n^{-1/2}$. In particular, we show that for the problem of transmitting i.i.d uniform bits over a binary symmetric channels with Hamming distortion, the smallest attainable distortion (bit error rate) is at least $\Omega(n^{-1/2})$ above the Asymptotic Value, if the ``bandwidth expansion ratio'' is above $1$.
Or Ordentlich - One of the best experts on this subject based on the ideXlab platform.
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a lower bound on the expected distortion of joint source channel coding
2020Co-Authors: Yuval Kochman, Or Ordentlich, Yury PolyanskiyAbstract:We consider the classic joint source-channel coding problem of transmitting a memoryless source over a memoryless channel. The focus of this work is on the long-standing open problem of finding the rate of convergence of the smallest attainable expected distortion to its Asymptotic Value, as a function of the blocklength $n$ . Our main result is that in general the convergence rate is not faster than $n^{-1/2}$ . In particular, we show that for the problem of transmitting i.i.d uniform bits over a binary symmetric channels with Hamming distortion, the smallest attainable distortion (bit error rate) is at least $\Omega (n^{-1/2})$ above the Asymptotic Value, if the “bandwidth expansion ratio” is above 1.
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a lower bound on the expected distortion of joint source channel coding
2019Co-Authors: Yuval Kochman, Or Ordentlich, Yury PolyanskiyAbstract:We consider the classic joint source-channel coding problem of transmitting a memoryless source over a memoryless channel. The focus of this work is on the rate of convergence of the smallest attainable expected distortion to its Asymptotic Value, as a function of blocklength n. Our main result is that in general the convergence rate is not faster than n−1/2. In particular, we show that for the problem of transmitting i.i.d uniform bits over a binary symmetric channels with Hamming distortion, the smallest attainable distortion (bit error rate) is at least Ω(n−1/2) above the Asymptotic Value, if the "bandwidth expansion ratio" is above 1.
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a lower bound on the expected distortion of joint source channel coding
2019Co-Authors: Yuval Kochman, Or Ordentlich, Yury PolyanskiyAbstract:We consider the classic joint source-channel coding problem of transmitting a memoryless source over a memoryless channel. The focus of this work is on the long-standing open problem of finding the rate of convergence of the smallest attainable expected distortion to its Asymptotic Value, as a function of blocklength $n$. Our main result is that in general the convergence rate is not faster than $n^{-1/2}$. In particular, we show that for the problem of transmitting i.i.d uniform bits over a binary symmetric channels with Hamming distortion, the smallest attainable distortion (bit error rate) is at least $\Omega(n^{-1/2})$ above the Asymptotic Value, if the ``bandwidth expansion ratio'' is above $1$.
