Scientific Series

We discuss the shortcomings of Einstein gravity at both the classical and quantum levels. We discuss the motivation for replacing Einstein gravity by conformal gravity. We show how the conformal gravity theory is able to naturally solve the quantum gravity problem, the vacuum zero-point energy problem, the vacuum zero-point pressure problem, the cosmological constant problem, and the dark matter problem. Central to its viability as aquantum theory is that the conformal theory is both renormalizable and unitary, with unitarity being obtained because the theory is a PTsymmetric rather than a Hermitian theory. We show that in the conformal theory there can be no a priori classical curvature, with all curvature having to result from quantization. In the conformal theory gravity requires no independent quantization of its own, with it being quantized solely by virtue of its being coupled to a quantized matter source. In the absence of quantum mechanics then there would thus be no gravity, with it being the desire to start with a classical gravity theory and then quantize it
that has prevented the construction of a sensible quantum gravity theory. We show that the macroscopic classical theory that results from the quantum conformal theory incorporates global physics effects coming from the material outside of galaxies (viz. the rest of theuniverse), global physics effects that are found to provide for a detailed accounting of a comprehensive set of 138
galactic rotation curves with no adjustable parameters other than galactic mass to light ratios, and with the need for no dark matter whatsoever. With these global effects eliminating the need for dark matter, we see that invoking dark matter in galaxies could potentially be nothing more than an attempt to describe global physics effects in purely local galactic terms.

This talk will be about non-equilibrium many-body physics in integer quantum Hall edge states far from equilibrium. Recent experiments have generated a highly non-thermal electron distribution by bringing together at a point contact two quantum Hall edge states originating from sources at different potentials. The relaxation of this distribution to a stationary form is observed as a function of distance downstream from the contact [Phys. Rev. Lett. 105, 056803 (2010)]. I will discuss the broader context for the experiments and a physical picture of the equilibration process. I will also present an exact treatment of a minimal model for the experiment with results that account well for the observations. [Joint work with Dmitry Kovrizhin]

We discuss the extension of the smooth entropy formalism to arbitrary physical systems with no bound on the number of degrees of freedom, comparing them with already existing notions of entropy for infinite-dimensional systems. Our analysis is both conceptual as well as based on operational primitives, for example we ask for the ability to perform privacy amplification against any kind of quantum side information.  As an application, we show how to employ a version of the entropic uncertainty relation to provide a security analysis for continuous variable quantum key distribution protocols.   based on arXiv:1107.5460, 1112.2179. This is joint work with Mario Berta, Fabian Furrer as well as with Torsten Franz, Marco Tomamichel, Reinhard Werner

The space of convex polyhedra can be given a dynamical structure. Exploiting this dynamics we have performed a Bohr-Sommerfeld quantization of the volume of a tetrahedral grain of space, which is in excellent agreement with loop gravity. Here we present investigations of the volume of a 5-faced convex polyhedron. We give for the first time a constructive method for finding these polyhedra given their face areas and normals to the faces and find an explicit formula for the volume. This results
in new information about cylindrical consistency in loop gravity and a couple of surprises about polyhedra. In particular, we are interested in discovering whether the evolution generated by this volume is chaotic or integrable as this will impact the interpretation of the spin network basis in loop gravity. 

There is strong theoretical evidence that black holes have a finite thermodynamic entropy equal to one quarter the area A of the horizon. Providing a microscopic derivation of the entropy of the horizon is a major task for a candidate theory of quantum gravity. Loop quantum gravity has been shown to provide a geometric explanation of the finiteness of the entropy and of the proportionality to the area of the horizon. The microstates are quantum geometries of the horizon. What has been missing until recently is the identification of the near-horizon quantum dynamics and a derivation of the universal form of the Bekenstein-Hawking entropy with its 1/4 prefactor. I report recent progress in this direction. In particular, I discuss the covariant spin foam dynamics and and show that the entropy of the quantum horizon reproduces the Bekenstein-Hawking entropy S=A/4 with the proper one-fourth coefficient for all values of the Immirzi parameter.