Related papers: Probing the Gravitational Scale via Running Gauge …
We consider a linearized, effective quantum theory of gravitation in which gravity weakens at energies higher than ~10^-3 eV in order to accommodate the apparent smallness of the cosmological constant. Such a theory predicts departures from…
Recent spectacular results of gravitational waves obtained by the LIGO system, with frequencies in the 100 Hz regime, make corresponding laboratory experiments with full control over cause and effect of great importance. Dynamic…
We describe the physics potential of $e^+e^-$ linear colliders in this report. These machines are planned to operate in the first phase at a center-of --mass energy of 500 GeV, before being scaled up to about 1 TeV. In the second phase of…
Quartic vertices provide a window into one of the most important problems in particle physics; the understanding of electroweak symmetry breaking. I survey the various processes that have been proposed to study quartic gauge boson couplings…
We examine how accurately the general HZV couplings, with V=Z,gamma, may be determined by studying e^+e^- --> Hff-bar processes at future e^+e^- linear colliders. By using the optimal-observable method, which makes use of all available…
The search for gravitational waves is one of today's major scientific endeavors. A gravitational wave can interact with matter by exciting vibrations of elastic bodies. Earth itself is a large elastic body whose so-called normal-mode…
It is argued that the next linear colliders can serve as W factories that may be exploited for precision tests on the properties of the massive gauge bosons. The connection between the probing of the symmetry breaking sector and precise…
We study the gravitational correction to the gauge couplings in the extra dimension model where the gravity propagates in the (4+n)-dimensional bulk. We show by explicit calculation in the background field method that the one-loop…
Asymptotically safe quantum fluctuations of gravity can uniquely determine the value of the gauge coupling for a large class of grand unified models. In turn, this makes the electromagnetic fine-structure constant calculable. The balance of…
The next generation of galaxy surveys will provide highly accurate measurements of the large-scale structure of the Universe, allowing for more stringent tests of gravity on cosmological scales. Higher order statistics are a valuable tool…
A new theory makes testable predictions: (1) Higgs fields have an unconventional equation of motion. (2) Fermions have a second-order coupling to gauge fields. (3) Fermion propagators are modified at high energy. (4) There are new scalar…
Using the current precision electroweak data, we look for the minimal particle content which is necessary to add to the standard model in order to have a complete unification of gauge couplings and gravity at the weakly coupled heterotic…
The cosmological constant presents one of the most fascinating and confounding problems in physics. A straightforward, seemingly robust prediction of quantum mechanics and general relativity is that the vacuum energy gravitates. Therefore,…
Precision measurements of the possible coupling of spin to other scalars, vectors and pseudovectors has proven to be a sensitive way to search for new particle physics beyond the standard model. Indeed, in addition to searching for exotic…
We describe a detailed study of the process $e^+e^- \to \ell\nu_\ell q \bar{q}$ and the measurement of tri-linear gauge boson couplings (TGV's) at LEP200 and at a 500~GeV and 1~TeV NLC. We included all tree level Feynman diagrams…
We investigate the scalar perturbations and the possible strong coupling issues of $f(T)$ around a cosmological background, applying the effective field theory (EFT) approach. We revisit the generalized EFT framework of modified…
All existing quantum gravity proposals share the same deep problem. Their predictions are extremely hard to test in practice. Quantum effects in the gravitational field are exceptionally small, unlike those in the electromagnetic field. The…
We investigate the dimension-8 gluonic quartic gauge couplings (gQGCs) at future high-energy muon colliders through the process $\mu^{+}\mu^{-}\!\to gg\gamma$. Using detailed event simulation and optimized kinematic selections, we derive…
In this paper we investigate a natural extension of the Standard Model that involves varying coupling constants. This is a general expectation in any fundamental theory such as string theory, and there are good reasons for why new physics…
In a quantum theory of gravity the gravitational Wilson loop, defined as a suitable quantum average of a parallel transport operator around a large near-planar loop, provides important information about the large-scale curvature properties…