nt - p h / 01 09 04 4 v 1 1 0 Se p 20 01 Particle localization and the Notion of Einstein Causality ∗
نویسنده
چکیده
The notion of Einstein causality, i.e. the limiting role of the velocity of light in the transmission of signals, is discussed. It is pointed out that Nimtz and coworkers use the notion of signal velocity in a different sense from Einstein and that their experimental results are in full agreement with Einstein causality in its ordinary sense. We also show that under quite general assumptions instantaneous spreading of particle localization occurs in quantum theory, relativistic or not, with fields or without. We discuss if this affects Einstein causality.
منابع مشابه
ua nt - p h / 01 11 06 0 v 1 9 N ov 2 00 1 Localization and causality for a free particle
Theorems (most notably by Hegerfeldt) prove that an initially localized particle whose time evolution is determined by a positive Hamiltonian will violate causality. We argue that this apparent paradox is resolved for a free particle described by either the Dirac equation or the Klein-Gordon equation because such a particle cannot be localized in the sense required by the theorems.
متن کاملar X iv : h ep - t h / 01 09 18 8 v 1 2 4 Se p 20 01 Curvature actions on Spin ( n ) bundles
We compute the number of linearly independent ways in which a tensor of Weyl type may act upon a given irreducible tensor-spinor bundle V over a Riemannian manifold. Together with the analogous but easier problem involving actions of tensors of Einstein type, this enumerates the possible curvature actions on V.
متن کاملHousehold food insecurity and diet diversity after the major 2010 landslide disaster in Eastern Uganda: a cross-sectional survey.
In 2010, a landslide in Bududa, Eastern Uganda, killed about 350 people and nearly 1000 affected households were resettled in Kiryandongo, Western Uganda. A cross-sectional survey assessed household food insecurity and diet diversity among 1078 affected and controls. In Bududa, the affected had a lower adjusted mean score of food insecurity than controls - 9·2 (se 0·4) v. 12·3 (se 0·4) (P<0·01)...
متن کاملar X iv : h ep - e x / 01 09 01 0 v 1 1 0 Se p 20 01 1 Color Transparency via Coherent Exclusive ρ 0 Production
We examine the potential of the COMPASS experiment at CERN to study color transparency via exclusive coherent vector meson production in hard muon-nucleus scattering. It is demonstrated that COMPASS has high sensitivity to test this important prediction of perturbative QCD.
متن کاملua nt - p h / 01 09 12 4 v 1 2 5 Se p 20 01 Mixed - state entanglement and quantum communication
We present basics of mixed-state entanglement theory. The first part of the article is devoted to mathematical characterizations of entangled states. In second part we discuss the question of using mixed-state entanglement for quantum communication. In particular, a type of entanglement that is not directly useful for quantum communcation (called bound entanglement) is analysed in detail. This ...
متن کامل