Experimental Search for Quantum Gravity 2012

Current approaches to the problems of dark energy and unification generically predict the existence of new fields (quintessence dilatons etc.) that will in principle couple with different strengths to different standard-model fields. These different coupling strengths will cause test materials of…

The high flux and variability of the blazar PKS 2155-304 as observed by H.E.S.S. during the night of 28 July 2006 allowed a very high precision search for Quantum Gravity-induced energy-dependent time lags. In this talk, I will review the results published by the H.E.S.S. collaboration on this topic…

Asymptotically safe inflation and CMB polarization The presence of complex critical exponents in the scaling behavior of the Newton constant and Cosmological constant has dramatic consequences at the inflation scale. In particular an infinite number of unstable de-Sitter vacua emerges from an…

One century after the seminal balloon flights of Victor Hess, the Pierre Auger Observatory aims at unveiling some of the mysteries of the highest-energy cosmic rays: what are their sources? Is there an end to the spectrum? What kind of particles are they? Are there signatures of new physics or of a…

Quantum Gravity at the origin of seeds of cosmic structure? This meeting shows a our impatience for uncovering at long last any signal of unknown physics that might have a quantum gravitational origin. I will argue that the transition from a homogenous and isotropic state characterizing the mid…

The IceCube Neutrino Observatory is a cubic-kilometer-scale neutrino detector built into the ice sheet at the geographic South Pole. Completed in December 2010, the detector consists of an array of photomultiplier tubes deployed along 86 cables ("strings") at depths of 1450 to 2450 m, as well as the…

Quantum-gravity effects as noise for gravity-wave detectors I discuss a mechanism that can allow Planck scale effects to manifest themselves as a source of lof-frequency noise for interferometers. The mechanism requires a discrete formulation of dynamics at the Planck scale. ____________________…

Dark Matter and Dark Energy as a Possible Manifestation of a Fundamental Scale If we take the idea of the Planck length as a fundamental (minimum) scale and if additionally we impose the Cosmological Constant ($Lambda$) as and infrared (IR) cut-off parameter. Then it is possible to demonstrate that…

Dynamical dimensional reduction and Asymptotic Safety The effective average action approach to Quantum Einstein Gravity (QEG) is discussed as a natural framework for exploring the scale dependent Riemannian geometry and multifractal micro-structure of the effective spacetimes predicted by QEG. Their…

Some recent searches for quantum gravity signatures using observations of distant astrophysical sources will be discussed, focusing on the search for Lorentz invariance violation (LIV) in the form of a dependence of the photon propagation speed on its energy. Fermi gamma-ray space telescope…