112,758 research outputs found
Quark number susceptibility of high temperature and finite density QCD
We utilize lattice simulations of the dimensionally reduced effective field
theory (EQCD) to determine the quark number susceptibility of QCD at high
temperature (). We also use analytic continuation to obtain results at
finite density. The results extrapolate well from known perturbative expansion
(accurate in extremely high temperatures) to 4d lower temperature lattice dataComment: 7 pages, 5 figures, Presented at the XXV International Symposium on
Lattice Field Theory, July 30 - August 4 2007, Regensburg, German
Influence of low energy scattering on loosely bound states
Compact algebraic equations are derived, which connect the binding energy and
the asymptotic normalization constant (ANC) of a subthreshold bound state with
the effective-range expansion of the corresponding partial wave. These
relations are established for positively-charged and neutral particles, using
the analytic continuation of the scattering (S) matrix in the complex
wave-number plane. Their accuracy is checked on simple local potential models
for the 16O+n, 16O+p and 12C+alpha nuclear systems, with exotic nuclei and
nuclear astrophysics applications in mind
Analytic continuation and physical content of the gluon propagator
The analytic continuation of the gluon propagator is revised in the light of
recent findings on the possible existence of complex conjugated poles. The
contribution of the anomalous pole must be added when Wick rotating, leading to
an effective Minkowskian propagator which is not given by the trivial analytic
continuation of the Euclidean function. The effective propagator has an
integral representation in terms of a spectral function which is naturally
related to a set of elementary (complex) eigenvalues of the Hamiltonian, thus
generalizing the usual K\"allen-Lehmann description. A simple toy model shows
how the elementary eigenvalues might be related to actual physical
quasiparticles of the non-perturbative vacuum.Comment: Editorially accepted version, with an entirely new introduction, a
figure on Wick rotation and many more reference
An application of the effective Sato-Tate conjecture
Based on the Lagarias-Odlyzko effectivization of the Chebotarev density
theorem, Kumar Murty gave an effective version of the Sato-Tate conjecture for
an elliptic curve conditional on analytic continuation and Riemann hypothesis
for the symmetric power -functions. We use Murty's analysis to give a
similar conditional effectivization of the generalized Sato-Tate conjecture for
an arbitrary motive. As an application, we give a conditional upper bound of
the form for the smallest prime at which two
given rational elliptic curves with conductor at most have Frobenius traces
of opposite sign.Comment: 12 pages; v2: refereed versio
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