We discuss the analytic continuation beyond μ T 1 in QCD at nonzero T and μ by use of the Pade’ approximants. The slope of the critical line obtained in this way increases at large μ with respect to the second order Taylor result.In the hot phase Pade’ and Taylor approximants coincide, suggesting a very large, and possibly infinite, radius of convergence of the Taylor series in this thermodynam...

Let [Sn] n=0 be such that Sn tS+ j=1 aj* n j as n , with 1>|*1 |> |*2 |> } } } , such that limj *j=0. A well-known result by Wynn states that when the Shanks transformation or its equivalent =-algorithm is applied to [Sn] n=0 , then = (n) 2k &Stak+1[> k i=1 (*k+1&*i) (1&*i)] 2 *k+1 as n . In the present work we extend this result (i) by allowing some of the *j to have the same modulus and (ii) ...

Abstract: In this paper, a comparison between h ig h e r order schemes has been performed in terms of numerical accuracy. Four finite difference schemes, the e xp lic it fourth-order compact Pade scheme, the implicit fourth-order Pade scheme, flowfield dependent variation (FDV) meth o d a n d h igh order compact flowfie ld dependent variation (HOC-FDV) scheme are tes ted. The FDV scheme is used...

With the emerging possibility to obtain emissions of triples GHZ-entangled photons via a direct parametric generation we study here bright this kind which involve higher order two triples, three etc. Such states would constitute natural generalization four mode (two beams plus polarization) squeezed vacuum. We have beam process emission generalized GHZ states, are superpositions one, two, three...

Ahsrruct: Section 1 describes the univariate situation in the case of non-normal Pade approximants and Cordellier’s extension of the famous five-star identity of Wynn. Section 2 repeats our definition of multivariate Pade approximants and proves a number of theorems that remain valid when going from the univariate to the multivariate case. These theorems and more new results given in Section 3....

We discuss the analytic continuation beyond μ/T ≃ 1 in QCD at nonzero T and μ by use of the Pade’ approximants. The slope of the critical line obtained in this way increases at large μ with respect to the second order Taylor result.In the hot phase Pade’ and Taylor approximants coincide, suggesting a very large, and possibly infinite, radius of convergence of the Taylor series in this thermodyn...