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[en] We show that a single experiment can test simultaneously and independently both the nonclassicality of states and of measurements by the violation or fulfillment of classical bounds on the statistics. Nonideal measurements affected by imperfections can be characterized by two bounds depending on whether we test the ideal measurement or the real one.
[en] Superselection rules (SSRs) constrain the allowed states and operations in quantum theory. They limit preparations and measurements and hence impact our ability to observe non-locality, in particular the violation of Bell inequalities. We show that a reference frame compatible with a particle number SSR does not allow observers to violate a Bell inequality if and only if it is prepared using only local operations and classical communication. In particular, jointly prepared separable reference frames are sufficient for obtaining violations of a Bell inequality. We study the size and non-local properties of such reference frames using superselection-induced variance. These results suggest the need for experimental Bell tests in the presence of superselection.
[en] Klyachko—Can—Binicioğlu—Shumovsky (KCBS) inequality is a Bell-like inequality, the violation of which can be used to confirm the existence of quantum contextuality. However, the imperfection of detection efficiency may cause the so-called loophole in actual KCBS's experiments. We derive an alternative KCBS inequality to deal with the loophole in actual KCBS's experiments. We prove that if the experimental data violate this KCBS inequality, the loophole-free violation of the original KCBS inequality will occur. We show that the minimum detection efficiency needed for a loophole-free violation of the KCBS inequality is about 0.9738
[en] Malley and Fine (Phys. Rev. A 2006 73 066102) discussed that all quantum observables would commute simultaneously if we accept a realistic theory of the Bell type (a local realistic theory) for quantum events, provided that all quantum events, including every quantum state and every observable (including every projector), are reproduced by a realistic theory of the Bell type for quantum events. We point out that their claim leads us to a contradiction. We study the relation between a local realistic theory and commutativity of quantum observables in a finite-dimensional space. We show that a realistic theory of the Bell type for quantum events does not impose the commutative algebraic structure into the set of all quantum observables if all quantum events are reproduced by a local realistic theory. We discuss that a violation of Bell locality is derived within a realistic theory of the Kochen–Specker type within quantum events. (paper)
[en] Full text: The puzzle of how time-reversible microscopic equations of mechanics lead to the time-irreversible macroscopic equations of thermodynamics has existed since the days of Boltzmann. Boltzmann simply side-stepped this paradox, stating as soon as one looks at bodies of small dimension, the validity of this theorem [the Second Law of Thermodynamics] must cease.' Today we state that the Fluctuation Theorem (FT) is a generalised, Second-Law like theorem that bridges the time-reversible and irreversible descriptions. Here we describe recent experiments where 'violations' in the Second Law occur over experimentally realisable time and length scales, consistent with the predictions of the FT. Copyright (2005) Australian Institute of Physics
[en] The origin of matter in the Universe is a fascinating cosmological puzzle that has triggered a formidable intellectual enterprise, started in 1967 with the prescient paper by Andrej Sakharov (1967 Pisma Zh. Eksp. Teor. Fiz. 5 32; 1967 JETP Lett. 52 4; 1991 Sov. Phys.—Usp. 34 392; 1991 Usp. Fiz. Nauk 161 61) aimed at relating a cosmological observation to the fundamental laws of physics, the goal of baryogenesis. A successful model of baryogenesis should ultimately identify the required source of charge parity violation and the origin of the cosmological matter–antimatter asymmetry. This focus issue is not only a review of the main ideas that have been proposed in baryogenesis but should also bear witness to the great vitality of the field and to show how future experimental results could bring a breakthrough in baryogenesis during the coming years. For this reason we selected, out of the multitude of proposed baryogenesis models, those that will more likely experience a significant experimental test during the coming years. (editorial)
[en] The recent results from Super-Kamiokande (SK) are reported. On atmospheric neutrino analysis, we have performed a full 3-flavor oscillation analysis with SK-I+II+III data. A CPT violation study on atmospheric neutrinois also done with SK-I+II+III data. On solar neutrino analysis, a 3-flavor oscillation analysis with SK-III data is performed.
[en] We derive the first law of thermodynamics using the method proposed by Wald. Treating the entropy as Noether charge and comparing with the usual first law of thermodynamics, we obtain explicitly the expression of entropy which contains infinitely many non-local terms (i.e. the integral terms). We have proved, in general, that the first law of black hole thermodynamics is violated for f(R,T) gravity. However, there might exist some special cases in which the first law for f(R, T) gravity is recovered. (authors)
[en] The nonlocality responsible for violations of Bell's inequalities is not equivalent to that used in teleportation, although they probably are two aspects of the same physical property. There are mixed states which do not violate any Bell type inequality, but still can be used for teleportation