Quantum Gravity: A Fluctuating Point of View

Relativistic Quantum Gravity at a Lifshitz Point

We show that the Hořava theory for the completion of General Relativity at UV scales can be interpreted as a gauge fixed Tensor-Vector theory, and it can be extended to an invariant theory under the full group of four-dimensional diffeomorphisms. In this respect, although being fully relativistic, it results to be locally anisotropic in the time-like and space-like directions defined by a famil...

Quantum Gravity at a Lifshitz Point

We present a candidate quantum field theory of gravity with dynamical critical exponent equal to z = 3 in the UV. (As in condensed matter systems, z measures the degree of anisotropy between space and time.) This theory, which at short distances describes interacting nonrelativistic gravitons, is power-counting renormalizable in 3 + 1 dimensions. When restricted to satisfy the condition of deta...

Fluctuating gravity of Earth's core.

F or centuries, we have known that Earth’s magnetic field varies with time. Edmond Halley (better known for his eponymous recurring comet) first recognized this time variation of magnetic compass needle direction and even offered a remarkable theory that required an intervening fluid between Earth’s solid outer shell and a hypothesized innermost solid core (1). For decades, consensus has emerge...

Infinite Random Graphs with a view towards Quantum Gravity

In this thesis we study random planar graphs and some of the tools and techniques used to address some related combinatorial problems. We give an account of generating function methods, mainly focusing on some analytic aspects of generating functions. Namely, we discuss the so-called singularity analysis process, a technique that allows the transfer of the singular behaviour of certain function...

Approaching the Planck Scale from a Generally Relativistic Point of View: a Philosophical Appraisal of Loop Quantum Gravity