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130
Geometric and Renormalized Entropy in Conformal Field Theory
 Nucl. Phys. B
, 1994
"... In statistical physics, useful notions of entropy are defined with respect to some coarse graining procedure over a microscopic model. Here we consider some special problems that arise when the microscopic model is taken to be relativistic quantum field theory. These problems are associated with the ..."
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Cited by 48 (0 self)
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In statistical physics, useful notions of entropy are defined with respect to some coarse graining procedure over a microscopic model. Here we consider some special problems that arise when the microscopic model is taken to be relativistic quantum field theory. These problems are associated with the existence of an infinite number of degrees of freedom per unit volume. Because of these the microscopic entropy can, and typically does, diverge for sharply localized states. However the difference in the entropy between two such states is better behaved, and for most purposes it is the useful quantity to consider. In particular, a renormalized entropy can be defined as the entropy relative to the ground state. We make these remarks quantitative and precise in a simple model situation: the states of a conformal quantum field theory excited by a moving mirror. From this work, we attempt to draw some lessons concerning the “information problem ” in black hole physics. 2
The Fluctuation Theorem
 Adv. Phys
, 2002
"... The question of how reversible microscopic equations of motion can lead to irreversible macroscopic behaviour has been one of the central issues in statistical mechanics for more than a century. The basic issues were known to Gibbs. ..."
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Cited by 40 (1 self)
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The question of how reversible microscopic equations of motion can lead to irreversible macroscopic behaviour has been one of the central issues in statistical mechanics for more than a century. The basic issues were known to Gibbs.
Science of chaos or chaos of science?
, 1996
"... I try to clarify several confusions in the popular literature concerning chaos, determinism, the arrow of time, entropy and the role of probability in physics. Classical ideas going back to Laplace and Boltzmann are explained and defended while some recent views on irreversibility, due to Prigogine, ..."
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Cited by 15 (0 self)
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I try to clarify several confusions in the popular literature concerning chaos, determinism, the arrow of time, entropy and the role of probability in physics. Classical ideas going back to Laplace and Boltzmann are explained and defended while some recent views on irreversibility, due to Prigogine, are criticized.
On causally asymmetric versions of Occam’s Razor and their relation to thermodynamics
, 2007
"... and their relation to thermodynamics ..."
Information and Entropy in Quantum Theory
, 2004
"... Recent developments in quantum computing have revived interest in the notion of information as a foundational principle in physics. It has been suggested that information provides a means of interpreting quantum theory and a means of understanding the role of entropy in thermodynamics. The thesis pr ..."
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Cited by 7 (5 self)
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Recent developments in quantum computing have revived interest in the notion of information as a foundational principle in physics. It has been suggested that information provides a means of interpreting quantum theory and a means of understanding the role of entropy in thermodynamics. The thesis presents a critical examination of these ideas, and contrasts the use of Shannon information with the concept of ’active information ’ introduced by Bohm and Hiley. We look at certain thought experiments based upon the ’delayed choice ’ and ’quantum eraser’ interference experiments, which present a complementarity between information gathered from a quantum measurement and interference effects. It has been argued that these experiments show the Bohm interpretation of quantum theory is untenable. We demonstrate that these experiments depend critically upon the assumption that a quantum optics device can operate as a measuring device, and show that, in the context of these experiments, it cannot be consistently understood in this way. By contrast, we then show how the notion of ’active information ’ in the Bohm interpretation provides a coherent explanation of the phenomena shown in these experiments. We then examine the relationship between information and entropy. The thought experiment
Geometric Algebra in Quantum Information Processing
 CONTEMPORARY MATHEMATICS
, 2002
"... This paper develops a geometric model for coupled twostate quantum systems (qubits) using geometric (aka Clifford) algebra. It begins by showing how Euclidean spinors can be interpreted as entities in the geometric algebra of a Euclidean vector space. This algebra is then lifted to Minkowski spac ..."
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Cited by 7 (3 self)
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This paper develops a geometric model for coupled twostate quantum systems (qubits) using geometric (aka Clifford) algebra. It begins by showing how Euclidean spinors can be interpreted as entities in the geometric algebra of a Euclidean vector space. This algebra is then lifted to Minkowski spacetime and its associated geometric algebra, and the insights this provides into how density operators and entanglement behave under Lorentz transformations are discussed. The direct sum of multiple copies of spacetime induces a tensor product structure on the associated algebra, in which a suitable quotient is isomorphic to the matrix algebra conventionally used in multiqubit quantum mechanics. Finally, the utility of geometric algebra in understanding both unitary and nonunitary quantum operations is demonstrated on several examples of interest in quantum information processing.
Theory and Simulation of Jump Dynamics, Diffusion and Phase Equilibrium in Nanopores
 Int. Rev. Phys. Chem
"... We review theory and simulation of rare event dynamics, di#usion and phase equilibrium in nanopores, focusing on benzene in NaX and NaY zeolites because of persistent experimental discrepancies. We discuss transition state theory and its application to zeoliteguest systems, suggesting that ca ..."
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Cited by 7 (2 self)
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We review theory and simulation of rare event dynamics, di#usion and phase equilibrium in nanopores, focusing on benzene in NaX and NaY zeolites because of persistent experimental discrepancies. We discuss transition state theory and its application to zeoliteguest systems, suggesting that calculations on flexible lattices and at finite guest loadings are important areas for future research. We consider manybody adsorption and di#usion in zeolites, focusing on the coupling between rare event dynamics and strong guestguest interactions. We explore the possibility that benzene can undergo phase transitions from low to high sorbate density in NaX, and find that this type of phase transition might explain intriguing loading dependencies of water and ammonia di#usion in terms of a subcritical droplet picture of adsorption in zeolites. We discuss various formulations of nonequilibrium di#usion through finite lattices, and describe a tracer counterpermeation simulation technique.