Related papers: The CPT-violating effects on neutron's gravitation…
Possible signals for indirect CPT violation arising in experiments with neutral kaons are considered in the context of a general CPT- and Lorentz-violating standard-model extension. Certain CPT observables can depend on the meson momentum…
Gravitationally bound neutrons have become an important tool in the experimental searches for new physics, such as modifications to Newton's force or candidates for dark matter particles. Here we include the relativistic effects of…
Among the four fundamental forces, only gravity does not couple to particle spins according to the general theory of relativity. We test this principle by searching for an anomalous scalar coupling between the neutron spin and the Earth…
The gravitational couplings of matter are studied in the presence of Lorentz and CPT violation. At leading order in the coefficients for Lorentz violation, the relativistic quantum hamiltonian is derived from the gravitationally coupled…
We study the effects of explicit spacetime-symmetry breaking on primordial tensor fluctuations using an effective-field theory for Lorentz/CPT violation. We find that the graviton is still massless, but that the propagation speed of tensor…
A model for spontaneous symmetry breaking using a specific form of the bumblebee model is analyzed in the context of a Schwarzschild background metric. The resulting back reaction of the symmetry-breaking field on the metric is computed to…
Sun's gravitation potential at earth varies during a year due to varying Earth-Sun distance. Comparing the results of very accurate measurements of atomic clock transitions performed at different time in the year allows us to study the…
The geometric phase (GP) acquired by a neutron passing through a uniform magnetic field elucidates a subtle interplay between its spatial and spin degrees of freedom. In the standard setup using thermal neutrons, the kinetic energy is much…
Understanding the nucleon spin structure in the regime where the strong interaction becomes truly strong poses a challenge to both experiment and theory. At energy scales below the nucleon mass of about 1 GeV, the intense interaction among…
At the supranuclear densities achieved inside a neutron star, matter may exhibit extreme properties. In particular, it may be the case that a suitable average of the speed of sound squared exceeds the so-called conformal limit, i.e.,…
We propose a simple phenomenological model predicting, through Lorentz symmetry breaking, a CPT-violating asymmetry between particle and antiparticle states in neutrino oscillations involving sterile neutrinos. Such a model is able to…
Violations of CPT invariance can induce neutrino-to-antineutrino transitions. We study this effect for solar neutrinos and use the upper bound on the solar neutrino-to-antineutrino transition probability from the KamLAND experiment to…
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…
We calculate the chameleon field potential for ultracold neutrons, bouncing on top of one or between two neutron mirrors in the gravitational field of the Earth. For the resulting non--linear equations of motion we give approximate…
Superfluid vortices pinned to nuclear lattice sites or magnetic flux tubes in a neutron star evolve abruptly through a sequence of metastable spatial configurations, punctuated by unpinning avalanches associated with rotational glitches, as…
A newly discovered instability in rotating neutron stars, driven by gravitational radiation reaction acting on the stars' $r$-modes, is shown here to set an upper limit on the spin rate of young neutron stars. We calculate the timescales…
The breakdown of Lorentz's and CPT invariance, as described by the Extension of the Standard Model, gives rise to a modification of the dispersion relation of particles. Consequences of such a modification are reviewed in the framework of…
This talk outlines some results for gravitational theories with local Lorentz violation in the context of the Lorentz- and CPT-violating Standard-Model Extension.
A discovery of gravitational waves from binary black holes raises a possibility that measurements of them can provide strict tests of CPT invariance in gravitational waves. When CPT violation exists, if any, gravitational waves with…
qBounce is using quantum states of ultra-cold neutrons in the gravitational field of the Earth to investigate gravitation in the micrometre range. We present current measurements taken in 2021 at the Institut Laue-Langevin (ILL) to…