arXiv subjects

Frans R. Klinkhamer

Publications and source records attributed to Frans R. Klinkhamer.

7 recordsLinked to original sources

arXiv2026

Big Bang revisited

The Friedmann cosmological solution of the standard Einstein gravitational field equation has a curvature singularity at a moment in time known as the Big Bang. It has been suggested that this Big Bang curvature singularity can be eliminated by use of a degenerate spacetime metric. This proposal was the main topic of our talk at the Workshop, but, here, we also discuss the possible appearance of CPT-conjugated worlds and the conjectured relevance of an extended version of Einstein's field equation.

gr-qc↗

arXiv2023

New Type of Traversable Wormhole

We review a new traversable-wormhole solution of the gravitational field equation of general relativity without exotic matter. Instead of having exotic matter to keep the wormhole throat open, the solution relies on a 3-dimensional "spacetime defect," which is characterized by a locally vanishing metric determinant. We also discuss the corresponding multiple-vacuum-defect-wormhole solution and possible experimental signatures from a "gas" of vacuum-defect wormholes. Multiple vacuum-defect wormholes appear to allow for backward time travel.

gr-qc↗

arXiv2006

Nontrivial spacetime topology, CPT violation, and photons

A physical mechanism for CPT violation is reviewed, which relies on chiral fermions, gauge interactions, and nontrivial spacetime topology. The nontrivial topology can occur at the very largest scale (e.g., at the "edge" of the universe) or at the very smallest scale (e.g., from a hypothetical spacetime foam). The anomalous effective gauge field action includes, most likely, a CPT-odd Chern-Simons-like term. Two phenomenological photon models with Abelian Chern-Simons-like terms are discussed.

hep-ph↗

arXiv2006

More on a possible energy dependence of Theta_13 in vacuum neutrino oscillations

Vacuum neutrino-oscillation probabilities from a simple three-flavor model with both mass-square differences and timelike Fermi-point splittings have been presented in a previous article [hep-ph/0504274]. Here, further results are given: first, for specific parameters relevant to MINOS in the low-energy mode and, then, for arbitrary parameters. A generalized model with equidistant Fermi-point splittings and an additional complex phase is also discussed. If relevant, this generalized model might have interesting effects at future long-baseline oscillation experiments.

hep-ph↗

arXiv2006

Lorentz-noninvariant neutrino oscillations: model and predictions

We present a three-parameter neutrino-oscillation model for three flavors of massless neutrinos with Fermi-point splitting and tri-maximal mixing angles. One of these parameters is the T-violating phase ε, for which the experimental results from K2K and KamLAND appear to favor a nonzero value. In this article, we give further model predictions for neutrino oscillations. Upcoming experiments will be able to test this simple model and the general idea of Fermi-point splitting. Possible implications for proposed experiments and neutrino factories are also discussed.

hep-ph↗

arXiv2005

Possible energy-dependence of Theta_13 in neutrino oscillations

A simple three-flavor neutrino-oscillation model is discussed which has both nonzero mass differences and timelike Fermi-point splittings, together with a combined bi-maximal and trimaximal mixing pattern. One possible consequence would be new effects in ν_μ \to ν_{e} oscillations, characterized by an energy-dependent effective mixing angle Θ_{13}. Future experiments such as T2K and NOvA, and perhaps even the current MINOS experiment, could look for these effects.

hep-ph↗

arXiv2005

Lorentz and CPT violation: a simple neutrino-oscillation model

We present a three-parameter model for three flavors of massless left-handed neutrinos with Fermi-point splitting and tri-maximal mixing angles. One of these parameters is the T-violating phase δ, for which the experimental results from K2K and KamLAND appear to favor a nonzero value. Future experiments, in particular MINOS, will be able to test this simple model. Possible implications for neutrino factories are briefly discussed.

hep-ph↗