72 research outputs found
Many-worlds interpretation of quantum theory, mesoscopic anthropic principle and biological evolution
No full textWe suggest to combine the Anthropic Principle with the Many-Worlds Interpretation of Quantum Theory. Realizing the multiplicity of worlds it provides an opportunity of explanation of some important events which are assumed to be extremely improbable. The Mesoscopic Anthropic Principle suggested here is aimed to explain appearance of such events which are necessary for emergence of Life and Mind. It is complementary to the Cosmological Anthropic Principle explaining the fine tuning of fundamental constants. We briefly discuss various possible applications of the Mesoscopic Anthropic Principle including the Solar Eclipses and assembling of complex molecules. Besides, we address the problem of Time's Arrow in the framework of the Many-Worlds Interpretation. We suggest the recipe for disentangling of quantities defined by fundamental physical laws and by an anthropic selection. The main emphasis is made on the problem of the biological evolution
Spin precession in anisotropic cosmologies
No full textWe consider the precession of a Dirac particle spin in some anisotropic Bianchi universes. This effect is present already in the Bianchi-I universe. We discuss in some detail the geodesics and the spin precession for both the Kasner and the Heckmann–Schucking solutions. In the Bianchi-IX universe the spin precession acquires the chaotic character due to the stochasticity of the oscillatory approach to the cosmological singularity. The related helicity flip of fermions in the very early universe may produce the sterile particles contributing to dark matter
Crossing and Radon tomography for generalized parton distributions
No full textThe crossing properties of the matrix elements of non-local operators, parameterized by generalized parton distribution, are considered. They are especially simple in terms of the double distributions which are common for the various kinematical regions. As a result, double distributions may be in principle extracted from the combined data in these regions by making use of the inverse Radon transform, known as a standard method in tomography. The ambiguities analogous to the ones for the vector potential in the two-dimensional magneto-statics are outlined. The possible generalizations are discussed. (C) 2001 Elsevier Science B.V. All rights reserved
Gauge invariance, causality and gluonic poles
No full textAbstractWe explore the electromagnetic gauge invariance of the hadron tensor of the Drell–Yan process with one transversely polarized hadron. The special role is played by the contour gauge for gluon fields. The prescription for the gluonic pole in the twist 3 correlator is related to causality property and compared with the prescriptions for exclusive hard processes. As a result we get the extra contributions, which naively do not have an imaginary phase. The single spin asymmetry for the Drell–Yan process is accordingly enhanced by the factor of two
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