We elaborate on the fact that quarkonium in hot QCD should not be thought of as a stationary bound state in a temperature-dependent real potential, but as a short-lived transient, with an exponentially decaying wave function. The reason is the existence of an imaginary part in the pertinent static potential, signalling the “disappearance”, due to inelastic scatterings with hard particles in the...

We consider Friedmann-Lemâıtre-Robertson-Walker cosmological models in the framework of general scalar-tensor theories of gravity (STG) with arbitrary coupling functions, set in the Jordan frame. First we describe the general properties of the phase space in the case of barotropic matter fluid and scalar field potential for any spatial curvature (flat, spherical, hyperbolic). Then we address th...

We calculate the scalar gravitational and matter perturbations in the context of slow-roll inflation with multiple scalar fields, that take values on a (curved) manifold, to first order in slow roll. For that purpose a basis for these perturbations determined by the background dynamics is introduced and multiple field slow-roll functions are defined. To obtain analytic solutions to first order,...

Full simulations of homogeneous isotropic turbulence containing a homogeneous passive scalar were made at low Reynolds numbers and various Prandtl numbers. The results show that the spectral behavior of the two fields are quite similar; both fields decay as power-law functions of time. However. the decay exponent is quite dependent on both the Reynolds and Prandtl numbers. The decay exponent of...

This paper provides new results about efficient arithmetic on (extended) Jacobiquartic form elliptic curves y = dx + 2ax + 1. Recent works have shown thatarithmetic on an elliptic curve in Jacobi quartic form can be performed solidly fasterthan the corresponding operations in Weierstrass form. These proposals use up to 7coordinates to represent a single point. However, fast scal...

We study polar quasinormal modes of relativistic stars in scalar-tensor theories, where we include a massive gravitational scalar field and employ the standard Brans-Dicke coupling function. For potential consider simple mass term as well associated with $R^2$ gravity. The presence makes spectrum much richer than General Relativity. here investigate radial ($l=0$) quadrupole ($l=2$). general $l...

For an arbitrary electromagnetic field, we define a prepotential S, which is a complexvalued function of spacetime. The prepotential is a modification of the two scalar potential functions introduced by E. T. Whittaker. The prepotential is Lorentz covariant under a spin half representation. For a moving charge and any observer, we obtain a complex dimensionless scalar. The prepotential is a fun...

We study an extended Gross-Neveu model with Nf quark flavors and with an additional SU(2) (global color) degree of freedom of the quarks. The four fermion interaction in the color channel is mediated by a random color matrix with fixed strength. The effective potential for the quark condensate and the scalar correlation function is investigated in the large Nf -limit. Quark antiquark thresholds...