Related papers: Gravitational physics with antimatter
This review is motivated by the first result of the ALPHA-g experiment at CERN, which indicates that atoms and anti-atoms have different gravitational charges; according to measurements, the gravitational acceleration of anti-atoms is only…
The Standard Model of elementary particles and their interactions does not include the gravitational interaction and faces problems in understanding of the dark matter, dark energy, strong CP violation etc. In continuing attempts to solve…
Some of the recent work on quantum gravity has involved modified uncertainty relations such that the products of the uncertainties of certain pairs of observables increase with time. It is here observed that this type of modified…
Violations of Lorentz symmetry are typically associated with modifications of one-particle dispersion relations. The physical effects of such modifications in particle collisions often grow with energy, so that ultrahigh-energy cosmic rays…
A general formalism is presented for violations of Lorentz and CPT symmetry in the neutrino sector. The effective hamiltonian for neutrino propagation in the presence of Lorentz and CPT violation is derived, and its properties are studied.…
A theoretical framework is introduced that describes possible CPT-violating effects in the context of quantum electrodynamics. Experiments comparing the anomalous magnetic moments of the electron and the positron can place tight limits on…
I review briefly various models and ways of Quantum-Gravity induced CPT violation, and discuss in some detail their phenomenology, in particular precision CPT tests in neutral mesons, and hydrogen/antihydrogen spectroscopy. As I shall…
Tiny violations of the Lorentz symmetry of relativity and the associated discrete CPT symmetry could emerge in a consistent theory of quantum gravity such as string theory. Recent evidence for linear polarization in gamma-ray bursts…
The field equations of a generalized $f(R)$ type gravity model, in which there is an arbitrary coupling between matter and geometry, are obtained. The equations of motion for test particles are derived from a variational principle in the…
We suggest that the eventual gravitational repulsion between matter and antimatter may be a key for understanding of the nature of dark matter and dark energy. If there is gravitational repulsion, virtual particle-antiparticle pairs in the…
This work is devoted to the discussion of an idea that gravitational interactions might be residual interactions of strong and electromagnetic interactions. Then, absence of the carriers of the gravitational interactions finds a natural…
A short review is given of some theoretical approaches to CPT violation. A potentially realistic possibility is that small apparent breaking of CPT and Lorentz symmetry could arise at the level of the standard model from spontaneous…
For most theories which parametrize modifications of General Relativity, including those which violate the equivalence principle, gravitational redshift tests typically offer weaker constraints on such test parameters than do precision…
The ALPHA collaboration recently published the article "Observation of the effects of gravity on the motion of antimatter" in issue 621 of Nature (2023), in which their conclusion states that "The probability that our data are consistent…
Standard Model extensions often predict low-mass and very weakly interacting particles, such as the axion. A number of small-scale experiments at the intensity/precision frontier are actively searching for these elusive particles,…
In this Chapter we illustrate the close connection between the violation of the weak equivalence principle typical of gravitational interactions at finite temperature, and similar violations induced by a breaking of the local Lorentz…
We show that Loop Quantum Gravity provides new mechanisms through which observed matter-antimatter asymmetry in the Universe can naturally arise at temperatures less than GUT scale. This is enabled through the introduction of a new length…
The gravitational forces exerted between fast neutrinos at short distances are examined using Newton's gravitational law, special relativity, and the equivalence principle. It is found that the magnitude of these forces is not negligible…
After a brief review of arguments in favor of antigravity (as gravitational repulsion between matter and antimatter) we present a simple idea for an experimental test using antiprotons. Different experimental realizations of the same basic…
The environment on the Moon has numerous features that make it interesting not only for the study of astrophysical phenomena, but also elementary particle physics. In fact, vacuum conditions, low gravity, and exposure to a relatively…