In generic Friedmann-Lema\^{\i}tre-Robertson-Walker spacetimes, states of low energy (SLEs) are defined to minimize the regularized density smeared along timelike curve an isotropic observer, which is specified via a smearing function. For every function, SLEs unique (up phase) and shown be exact Hadamard states. this work, we investigate viability as vacuum for cosmological perturbations in hy...

I survey a number of interesting tests of quantum chro-modynamics at the amplitude level which can be carried out in electron-positron annihilation and in photon-photon collisions at low energy. Some of the tests require e + e − center of mass energy as small as √ s = 2 GeV. Other tests which involve a spectrum of energies can be carried out advantageously at high energy facilities using the ra...

A brief review is given of the use of duality symmetries to form orbits of supergravity black-hole solutions and their relation to extremal (i.e. BPS) solutions at the limits of such orbits. An important technique in this analysis uses a timelike dimensional reduction and exchanges the stationary black-hole problem for a nonlinear sigma-model problem. Families of BPS solutions are characterized...

Form factors of the proton, pion, and kaon for large timelike momentum transfers have recently been measured with precision. The results and future prospects are discussed.