The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform
Ting-gao Yang - One of the best experts on this subject based on the ideXlab platform.
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using pulsar timing arrays and the quantum Normalization Condition to constrain relic gravitational waves
Classical and Quantum Gravity, 2014Co-Authors: Ming-lei Tong, Yang Zhang, Wen Zhao, Jinzhong Liu, Cheng-shi Zhao, Ting-gao YangAbstract:In the non-standard model of relic gravitational waves (RGWs) generated in the early universe, the theoretical spectrum is mainly described by an amplitude r and a spectral index beta, the latter usually being determined by the slope of the inflaton potential. Pulsar timing arrays (PTAs) data have imposed constraints on the amplitude of strain spectrum for a power-law form as a phenomenological model. Applying these constraints to a generic, theoretical spectrum with r and beta as independent parameters, we convert the PTAs constraint into an upper bound on the index beta, which turns out to be less stringent than those upper bounds from the Big Bang nucleosynthesis, cosmic microwave background and LIGO/VIRGO, respectively. Moreover, it is found that PTAs constrain the nonstandard RGWs more stringently than the standard RGWs. If the Condition of the quantum Normalization is imposed upon a theoretical spectrum of RGWs, r and beta become related. With this Condition, a minimum requirement of the horizon size during inflation is greater than the Planck length that results in an upper bound on beta, which is comparable in magnitude to that by PTAs. When both PTAs and the quantum Normalization are applied to a theoretical spectrum of RGWs, constraints can be obtained for other cosmic processes of the early universe, such as the reheating, a process less understood observationally so far. The resulting constraint is consistent with the slow-roll, massive scalar inflation model. The future square kilometer array will be able to constrain RGWs further and might even detect RGWs, rendering an important probe to the very early universe.
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Using pulsar timing arrays and the quantum Normalization Condition to constrain relic gravitational waves
Classical and Quantum Gravity, 2013Co-Authors: Ming-lei Tong, Yang Zhang, Wen Zhao, Jinzhong Liu, Cheng-shi Zhao, Ting-gao YangAbstract:In the non-standard model of relic gravitational waves (RGWs) generated in the early universe, the theoretical spectrum of is mainly described by an amplitude $r$ and a spectral index $\beta$, the latter usually being determined by the slope of the inflation potential. Pulsar timing arrays (PTAs) data have imposed constraints on the amplitude of strain spectrum for a power-law form as a phenomenological model. Applying these constraints to a generic, theoretical spectrum with $r$ and $\beta$ as independent parameters, we convert the PTAs constraint into an upper bound on the index $\beta$, which turns out to be less stringent than those upper bounds from BBN, CMB, and LIGO/VIRGO, respectively. Moreover, it is found that PTAs constrain the non-standard RGWs more stringent than the standard RGWs. If the Condition of the quantum Normalization is imposed upon a theoretical spectrum of RGWs, $r$ and $\beta$ become related. With this Condition, a minimum requirement of the horizon size during inflation is greater than the Planck length results in an upper bound on $\beta$, which is comparable in magnitude to that by PTAs. When both PTAs and the quantum Normalization are applied to a theoretical spectrum of RGWs, constraints can be obtained for other cosmic processes of the early universe, such as the reheating, a process less understood observationally so far. The resulting constraint is consistent with the slow-roll, massive scalar inflation model. The future SKA will be able to constrain RGWs further and might even detect RGWs, rendering an important probe to the very early universe.
George Soklis - One of the best experts on this subject based on the ideXlab platform.
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SHAPE OF WAGE-PROFIT CURVES IN JOINT PRODUCTION SYSTEMS: EVIDENCE FROM THE SUPPLY AND USE TABLES OF THE FINNISH ECONOMY: Shape of Wage-profit Curves in Joint Production Systems
Metroeconomica, 2011Co-Authors: George SoklisAbstract:This paper extends the empirical investigation of the shape of wage–profit curves to the case of joint production using data from the Supply and Use Tables of the Finnish economy (for the years 1995 through 2004). It is found that (i) the considered systems do not have the usual properties of single-product systems, and (ii) the monotonicity of the wage–profit curves depends on the adopted Normalization Condition.
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Wage-profit curves of the Finnish economy: evidence from the supply and use tables
2011Co-Authors: George SoklisAbstract:This paper extends the empirical investigation of the shape of wage-profit curves to the case of joint production using data from the Supply and Use Tables of the Finnish economy (for the years 1995 through 2004). It is found that (i) the considered systems do not have the usual properties of single-product systems; and (ii) the monotonicity of the wage-profit curves depends on the adopted Normalization Condition.
Ming-lei Tong - One of the best experts on this subject based on the ideXlab platform.
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using pulsar timing arrays and the quantum Normalization Condition to constrain relic gravitational waves
Classical and Quantum Gravity, 2014Co-Authors: Ming-lei Tong, Yang Zhang, Wen Zhao, Jinzhong Liu, Cheng-shi Zhao, Ting-gao YangAbstract:In the non-standard model of relic gravitational waves (RGWs) generated in the early universe, the theoretical spectrum is mainly described by an amplitude r and a spectral index beta, the latter usually being determined by the slope of the inflaton potential. Pulsar timing arrays (PTAs) data have imposed constraints on the amplitude of strain spectrum for a power-law form as a phenomenological model. Applying these constraints to a generic, theoretical spectrum with r and beta as independent parameters, we convert the PTAs constraint into an upper bound on the index beta, which turns out to be less stringent than those upper bounds from the Big Bang nucleosynthesis, cosmic microwave background and LIGO/VIRGO, respectively. Moreover, it is found that PTAs constrain the nonstandard RGWs more stringently than the standard RGWs. If the Condition of the quantum Normalization is imposed upon a theoretical spectrum of RGWs, r and beta become related. With this Condition, a minimum requirement of the horizon size during inflation is greater than the Planck length that results in an upper bound on beta, which is comparable in magnitude to that by PTAs. When both PTAs and the quantum Normalization are applied to a theoretical spectrum of RGWs, constraints can be obtained for other cosmic processes of the early universe, such as the reheating, a process less understood observationally so far. The resulting constraint is consistent with the slow-roll, massive scalar inflation model. The future square kilometer array will be able to constrain RGWs further and might even detect RGWs, rendering an important probe to the very early universe.
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Using pulsar timing arrays and the quantum Normalization Condition to constrain relic gravitational waves
Classical and Quantum Gravity, 2013Co-Authors: Ming-lei Tong, Yang Zhang, Wen Zhao, Jinzhong Liu, Cheng-shi Zhao, Ting-gao YangAbstract:In the non-standard model of relic gravitational waves (RGWs) generated in the early universe, the theoretical spectrum of is mainly described by an amplitude $r$ and a spectral index $\beta$, the latter usually being determined by the slope of the inflation potential. Pulsar timing arrays (PTAs) data have imposed constraints on the amplitude of strain spectrum for a power-law form as a phenomenological model. Applying these constraints to a generic, theoretical spectrum with $r$ and $\beta$ as independent parameters, we convert the PTAs constraint into an upper bound on the index $\beta$, which turns out to be less stringent than those upper bounds from BBN, CMB, and LIGO/VIRGO, respectively. Moreover, it is found that PTAs constrain the non-standard RGWs more stringent than the standard RGWs. If the Condition of the quantum Normalization is imposed upon a theoretical spectrum of RGWs, $r$ and $\beta$ become related. With this Condition, a minimum requirement of the horizon size during inflation is greater than the Planck length results in an upper bound on $\beta$, which is comparable in magnitude to that by PTAs. When both PTAs and the quantum Normalization are applied to a theoretical spectrum of RGWs, constraints can be obtained for other cosmic processes of the early universe, such as the reheating, a process less understood observationally so far. The resulting constraint is consistent with the slow-roll, massive scalar inflation model. The future SKA will be able to constrain RGWs further and might even detect RGWs, rendering an important probe to the very early universe.
Saba Noor - One of the best experts on this subject based on the ideXlab platform.
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Erratum to: Wave-function-based characteristics of hybrid mesons
The European Physical Journal A, 2014Co-Authors: Nosheen Akbar, Bilal Masud, Saba NoorAbstract:1) The normalized radial wave functions in figs. 1, 5 and 6 were plotted by using the Normalization Condition ∫ R R = 1 instead of ∫ U U = 1. Here we revised the calculations for radial wave functions by using the correct Normalization Condition. All other results presented in the paper remain unaffected, except for the radial wave functions at origin in the fourth column of table 10 of the original publication. The revised figures and magnitudes of radial wave functions at origin are reported in the following figures and table. 2) ∇2 in eq. (3) should be replaced with d2 dr2 . 3) In eq. (4), 〈r2〉 should be replaced by √ 〈r2〉. 4) In the paragraph after eq. (6), the symbol m is replaced by μ.
Peter D Miller - One of the best experts on this subject based on the ideXlab platform.
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the steepest descent method and the asymptotic behavior of polynomials orthogonal on the unit circle with fixed and exponentially varying nonanalytic weights
International Mathematics Research Papers, 2010Co-Authors: Kenneth D T Mclaughlin, Peter D MillerAbstract:The steepest descent method for asymptotic analysis of matrix Riemann-Hilbert problems was introduced by Deift and Zhou in 1993 [14]. A matrix Riemann-Hilbert problem is specified by giving a triple (Σ, v,N) consisting of an oriented contour Σ in the complex z-plane, a matrix function v : Σ → SL(N) which is usually taken to be continuous except at self-intersection points of Σwhere a certain compatibility Condition is required, and a Normalization Condition N as z → ∞. If Σ is not bounded, certain asymptotic Conditions are required of v in order to have compatibility with the Normalization Condition. Consider an analytic functionM : C \ Σ → SL(N) taking continuous boundary valuesM+(z) (resp., M−(z)) on Σ from the left (resp., right). The Riemann-Hilbert problem (Σ, v,N) is then to find such a matrix M(z) satisfying the Normalization Condition N as z → ∞ and the jump Condition M+(z) = M−(z)v(z) whenever z is a non-self-intersection point of Σ (so the left and right boundary values are indeed well defined). The steepest descent method of Deift and Zhou applies to certain Riemann-Hilbert problems where the jumpmatrix v(z) depends on an auxiliary control parameter, and is a method for extracting asymptotic properties of the solution M(z) (and indeed proving the existence and
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The ∂ Steepest Descent Method and the Asymptotic Behavior of Polynomials Orthogonal on the Unit Circle with Fixed and Exponentially Varying Nonanalytic Weights
International Mathematics Research Papers, 2010Co-Authors: K. T.-r. Mclaughlin, Peter D MillerAbstract:The steepest descent method for asymptotic analysis of matrix Riemann-Hilbert problems was introduced by Deift and Zhou in 1993 [14]. A matrix Riemann-Hilbert problem is specified by giving a triple (Σ, v,N) consisting of an oriented contour Σ in the complex z-plane, a matrix function v : Σ → SL(N) which is usually taken to be continuous except at self-intersection points of Σwhere a certain compatibility Condition is required, and a Normalization Condition N as z → ∞. If Σ is not bounded, certain asymptotic Conditions are required of v in order to have compatibility with the Normalization Condition. Consider an analytic functionM : C \ Σ → SL(N) taking continuous boundary valuesM+(z) (resp., M−(z)) on Σ from the left (resp., right). The Riemann-Hilbert problem (Σ, v,N) is then to find such a matrix M(z) satisfying the Normalization Condition N as z → ∞ and the jump Condition M+(z) = M−(z)v(z) whenever z is a non-self-intersection point of Σ (so the left and right boundary values are indeed well defined). The steepest descent method of Deift and Zhou applies to certain Riemann-Hilbert problems where the jumpmatrix v(z) depends on an auxiliary control parameter, and is a method for extracting asymptotic properties of the solution M(z) (and indeed proving the existence and
