No abstract

We consider a discrete model of Euclidean quantum gravity in three dimensions based on a summation over random simplicial manifolds. We derive some elementary properties of the model and discuss possible “matrix” models for 3-D gravity.

T.djvu Quantum well lasers-Zory P.Sdjvu Formats and Editions of Quantum geometry: a statistical field theory. Jul 12, 2006. Statistical Mechanics in Relation to Field Theory B. Durhuus, and T. Jonsson, Quantum geometry: A statistical field theory approach, Cam-. Proceedings of the American Mathematical Society ?Publication Quantum geometry. A statistical field theory approach. Reprint of the 1997 hardback ed. Models of random geometry and random matrices have wide applications, ranging. and T. Jonsson, Quantum Geometry-A statistical field theory approach. Quantum Geometry: A Statistical Field Theory Approach Jan.-eBay This book is about the influence of chance and fluctuating shape in quantum physics. It covers new research in some of the most exciting developments in Perspectives in Statistical Mechanics Quantum geometry: a statistical field theory. by Jan Ambjørn • Quantum geometry: a statistical field theory approach. by Jan Ambjørn Bergfinnur J Durhuus M-Theory and Quantum Geometry-Google Books Result 6 days ago. Download Quantum Geometry-A Statistical Field Theory Approach-Ambje, torrent or any other torrent from Pictures category. A Statistical Field Theory Approach-Ambje.-Kickass Torrents Nov 17, 2005. mology, black hole mechanics, quantum field theory in curved failure of the standard perturbative approach to quantum gravity may The detailed theory of the quantum horizon geometry and the standard statistical. Boundary Conformal Field Theory and the Worldsheet Approach to.

No abstract

Abstract. We develop techniques to obtain rigorous bounds on the behaviour of random walks on combs. Using these bounds we calculate exactly the spectral dimension of random combs with infinite teeth at random positions or teeth with random but finite length. We also calculate exactly the spectral dimension of some fixed non-translationally invariant combs. We relate the spectral dimension to the critical exponent of the mass of the two-point function for random walks on random combs, and compute mean displacements as a function of walk duration. We prove that the mean first passage time is generally infinite for combs with anomalous spectral dimension.1 durhuus@math.ku.dk 2 thjons@raunvis.hi.is

Abstract. We define generic ensembles of infinite trees. These are limits as N → ∞ of ensembles of finite trees of fixed size N, defined in terms of a set of branching weights. Among these ensembles are those supported on trees with vertices of a uniformly bounded order. The associated probability measures are supported on trees with a single spine and Hausdorff dimension d h = 2. Our main result is that their spectral dimension is d s = 4/3, and that the critical exponent of the mass, defined as the exponential decay rate of the two-point function along the spine, is 1/3.

The metric of two-dimensional quantum gravity interacting with conformal matter is believed to collapse to a branched polymer metric when the central charge c > 1. We show analytically that the spectral dimension, d S , of such a branched polymer phase is 4 3 . This is in good agreement with numerical simulations for large c.

Magma flow during volcanic eruptions causes surface deformation that can be used to constrain the location, geometry and internal pressure evolution of the underlying magmatic source 1 . The height of the volcanic plumes during explosive eruptions also varies with magma flow rate, in a nonlinear way 2,3 . In May 2011, an explosive eruption at Grímsvötn Volcano, Iceland, erupted about 0.27 km 3 denserock equivalent of basaltic magma in an eruption plume that was about 20 km high. Here we use Global Positioning System (GPS) and tilt data, measured before and during the eruption at Grímsvötn Volcano, to show that the rate of pressure change in an underlying magma chamber correlates with the height of the volcanic plume over the course of the eruption. We interpret ground deformation of the volcano, measured by geodesy, to result from a pressure drop within a magma chamber at about 1.7 km depth. We estimate the rate of magma discharge and the associated evolution of the plume height by differentiating the co-eruptive pressure drop with time. The time from the initiation of the pressure drop to the onset of the eruption was about 60 min, with about 25% of the total pressure change preceding the eruption. Near-real-time geodetic observations can thus be useful for both timely eruption warnings and for constraining the evolution of volcanic plumes.