Related papers: Some Remarks on Theories with Large Compact Dimens…
Recently it has been pointed out that the characteristic quantum-gravity scale could be as low as the weak scale in theories with gravity propagating in higher dimensions. The observed smallness of Newton's constant is a consequence of the…
The idea that quantum gravity can be realized at the TeV scale is extremely attractive to theorists and experimentalists alike. This proposal leads to extra spacial dimensions large compared to the electroweak scale. Here we give a very…
A unified theory of four-dimensional gravity together with the standard model is presented, with supersymmetry breaking of M-theory at a TeV. Masses of the the known particles are derived. The cosmological constant is quantum generated to…
The possible existence of bulk singlet neutrinos in the scenario with large compactified dimensions and low string scale $M_*$ has important consequences for low-energy observables. We demonstrate that intergenerational mass splitting and…
We study graviton scattering in the presence of higher dimensional operators - particularly, R^4 - arising from loop effects. We find that the results do not correspond to any known terms in the effective action of Matrix Theory, thus…
If the Planck scale is near a TeV, black hole production should be possible at colliders, as well as by cosmic rays. I begin with a review of the two approaches to TeV-scale gravity, large extra dimensions and warped compactification,…
Quantum gravity places entirely new challenges on the formulation of a consistent theory as well as on an extraction of potentially observable effects. Quantum corrections due to the gravitational field are commonly expected to be tiny…
Whenever fields are allowed to propagate in different portions of space-time, the four dimensional theory exhibits an effective violation of the principle of equivalence. We discuss the conditions under which such an effect is relevant for…
In this paper, the general features of the neutrino sector in TeV scale quantum gravity theories, such as ADD and Many Species Theory, is investigated. This class of theories has an inherent way to generate small neutrino masses. After…
A recently conjectured relashionship between UV and IR cutoffs in an effective field theory without quantum gravity is generalized in the presence of large extra dimensions. Estimates for the corrections to the usual calculation of…
We review the implications of modern higher-dimensional theories of gravity for astrophysics and cosmology. In particular, we discuss the latest developments of space-time-matter theory in connection with dark matter, particle dynamics and…
Quantum gravity places important consistency conditions on low-energy effective field theory, such as the absence of global symmetries. These may have important consequences in the search for particle physics beyond the Standard Model. We…
If there are large extra dimensions and the fundamental Planck scale is at the TeV scale, then the question arises of whether ultra-high energy cosmic rays might probe them. We study the neutrino-nucleon cross section in these models. The…
The aim of this article is to review the recent developments in the phenomenology of quantum gravity at the Large Hadron Collider. We shall pay special attention to four-dimensional models which are able to lower the reduced Planck mass to…
In scenarios with extra dimensions the gravitational interaction may become strong at TeV energies. This could modify the $\nu$$N$ cross section and imply distinct signals at neutrino telescopes. In particular, cosmogenic neutrinos of…
It is argued that the surface radius of a compact source can not be less than its gravitational radius due to the strong gravitational time dilation effects. The such "topological" difference between the Newtonian and relativistic gravity…
The unification of gravity to the other forces has been a major problem for most of the last century. I use a modification to Newtonian gravitation to extract the strong and weak nuclear coupling constants. Some of the possible implications…
Astonishing cancellations take place in the calculation of high-energy scattering cross sections in quantum quadratic gravity, a quantum field theory for gravity. Tree-level differential cross sections that are minimally inclusive behave as…
Recently, an increasing interest in UV/IR mixing phenomena has drawn attention to the range of validity of standard quantum field theory. Here we explore the consequences of such a limited range of validity in the context of radiative…
The origin and nature of ultrahigh-energy cosmic ray events, above the Greisen-Zatsepin-Kuzmin (GZK) cutoff energy, constitute a long-standing, unsolved mistery. Neutrinos are proposed candidates but their standard interactions with matter…