ar X iv : h ep - t h / 96 04 07 8 v 1 1 5 A pr 1 99 6 ITEP

ar X iv : h ep - t h / 96 04 15 9 v 1 2 5 A pr 1 99 6 BGU - PH - 96 / 08 SPECTRUM OF COSMIC GRAVITATIONAL WAVE BACKGROUND

Models of string cosmology predict a stochastic background of gravitational waves with a spectrum that is strongly tilted towards high frequencies. I give simple approximate expressions for spectral densities of the cosmic background which can be directly compared with sensitivities of gravitational wave detectors.

ar X iv : h ep - p h / 98 04 40 7 v 1 2 6 A pr 1 99 8 B c → l ν̄γ DECAY IN LIGHT CONE QCD

ar X iv : h ep - p h / 96 04 36 7 v 2 5 J un 1 99 6 Preprint ITEP – 10 / 96 - TH Physics of Quark – Gluon Plasma

In this lecture, we give a brief review of what theorists now know, understand, or guess about static and kinetic properties of quark–gluon plasma. A particular attention is payed to the problem of physical observability, i.e. the physical meaningfulness of various characteristics of QGP discussed in the literature.

ar X iv : h ep - t h / 96 04 04 9 v 1 9 A pr 1 99 6 The exponential map of GL ( N )

A finite expansion of the exponential map for a N ×N matrix is presented. The method uses the Cayley-Hamilton theorem for writing the higher matrix powers in terms of the first N-1 ones. The resulting sums over the corresponding coefficients are rational functions of the eigenvalues of the matrix. ∗ e-mail [email protected]

ar X iv : h ep - p h / 96 04 34 4 v 1 1 7 A pr 1 99 6 LEP 1 - LEP 2 : THEORY VERSUS EXPERIMENT ∗

The status of the standard model is briefly reviewed in the light of the most recent set of experimental data, with particular emphasis to the limits on the Higgs boson mass. The search for a light Higgs boson at LEP 2 is also briefly analyzed.