相关论文: Phenomenological constraints on low-scale gravity
Massive gravity in the weak field limit is described by the Fierz-Pauli theory with 5 degrees of freedom in four dimensions. In this theory, we calculate the gravitomagnetic effects (potential energy) between two point-like, spinning…
Tensor-scalar theories of gravitation are commonly employed as extensions of General Relativity that allow to describe a much wider phenomenology. They are also naturally generated as low energy limit of higher-dimensional or unified…
We set an upper bound on the gravitational cutoff in theories with exact quantum numbers of large N periodicity, such as Z_N discrete symmetries. The bound stems from black hole physics. It is similar to the bound appearing in theories with…
We study some phenomenological implications of models where the scale of quantum gravity effects lies much below the four-dimensional Planck scale. These models arise from M-theory vacua where either the internal space volume is large or…
An upper limit to non-Newtonian attracive forces is obtained from the measurement of quantum states of neutrons in the Earth's gravitational field. This limit improves the existing constrains in the nanometer range.
In the presence of large extra dimensions, the fundamental Planck scale can be much lower than the apparent four-dimensional Planck scale. In this setup, the weak gravity conjecture implies a much more stringent constraint on the UV cutoff…
Basing on the field theory of gravity and observable parameters of the expanding Universe the upper limit of $m_g \leq 4.5 . 10^{-66} g$. on the value of possible graviton mass is derived.
Treating the MSSM as an effective theory, we study the implications of having dimension five operators in the superpotential for flavor and CP-violating processes, exploiting the linear decoupling of observable effects with respect to the…
A novel constraint on $f(R)$ theories of gravity is obtained from the gravitational wave signal emitted from the binary neutron star merger event GW170817. The $f(R)$ theories possess an additional massive scalar degree of freedom apart…
I review the relations between mass scales in various string theories and in M-theory. I discuss physical motivations and possible consistent realizations of large volume compactifications and low string scale. Large longitudinal…
We find a new class of theories of massive gravity with five propagating degrees of freedom where only rotations are preserved. Our results are based on a non-perturbative and background-independent Hamiltonian analysis. In these theories…
The hierarchy problem in particle physics has recently been approached from a geometric point of view in different models. These approaches postulate the existence of extra dimensions with various geometric properties, to explain how the…
Gravity differs from all other known fundamental forces since it is best described as a curvature of spacetime. For that reason it remains resistant to unifications with quantum theory. Gravitational interaction is fundamentally weak and…
Recently, a measurement of the pressure distribution experienced by the quarks inside the proton has found a strong repulsive (positive) pressure at distances up to 0.6 femtometers from its center and a (negative) confining pressure at…
Weak gravitational lensing provides a means of testing the long-range properties of gravity. Current measurements are consistent with standard Newtonian gravity and inconsistent with substantial modifications on Mpc scales. The data allows…
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…
The gravitational interactions of elementary particles are suppressed by the Planck scale M_P ~ 10^18 GeV and are typically expected to be far too weak to be probed by experiments. We show that, contrary to conventional wisdom, such…
Generic violations of Lorentz symmetry can be described by an effective field theory framework that contains both general relativity and the standard model of particle physics called the Standard-Model Extension (SME). We obtain new…
Leptons, quarks and gauge bosons are assumed to be described by local field theory. Stringent bounds on nonlocal scale can be derived from the high- presision LEP measurements. We find a bound on nonlocal scale $\Lambda_{nl} > 1020\: Gev$,…
We construct an anomaly-free extension of the left-right symmetric model, where the maximal flavor group is gauged and anomaly cancellation is guaranteed by adding new vectorlike fermion states. We address the question of the lowest allowed…