Fundamental time asymmetry from nontrivial space topology

It is argued that a fundamental time asymmetry could arise from the global structure of the space manifold. The proposed mechanism relies on the CPT anomaly of certain chiral gauge theories defined over a multiply connected space manifold. The resulting time asymmetry (microscopic arrow of time) is illustrated by a simple thought experiment. The effect could, in principle, play a role in determining the initial conditions of the big bang.Comment: 9 pages, REVTeX, v5: version publishe

Models for low-energy Lorentz violation in the photon sector: Addendum to 'Consistency of isotropic modified Maxwell theory'

In a previous article [arXiv:1011.4258], we established the consistency of isotropic modified Maxwell theory for a finite range of the Lorentz-violating parameter \tilde{kappa}_{tr}, which includes both positive and negative values of \tilde{kappa}_{tr}. As an aside, we mentioned the existence of a physical model which, for low-energy photons, gives rise to isotropic modified Maxwell theory with a positive parameter \tilde{kappa}_{tr} (corresponding to a "slow" photon). Here, we present a related model which gives rise to isotropic modified Maxwell theory with a negative parameter \tilde{kappa}_{tr} (corresponding to a "fast" photon). Both models have an identical particle content, photon and Dirac particles, but differ in the type of spacetime manifold considered.Comment: 6 pages, v4: published versio

A New Perspective on Electroweak Strings

The vortex solution (Z-string) of the electroweak interactions can be interpreted as the 2-dimensional sphaleron at the top of a non-contractible sphere. The same holds for another type of solution, the W-string.Comment: 13 pages, Latex, NIKHEF-H/94-02 (February 2, 1994), 1 figure available by fax or mail (send request to [email protected]

Maxwell-Chern-Simons theory for curved spacetime backgrounds

We consider a modified version of four-dimensional electrodynamics, which has a photonic Chern-Simons-like term with spacelike background vector in the action. Light propagation in curved spacetime backgrounds is discussed using the geometrical-optics approximation. The corresponding light path is modified, which allows for new effects. In a Schwarzschild background, for example, there now exist stable bounded orbits of light rays and the two polarization modes of light rays in unbounded orbits can have different gravitational redshifts. An Erratum with important corrections has been published, which appears as Appendix E in this arXiv version.Comment: 28 pages with elsart, v6: published version of paper and Erratu

Construction of a New Electroweak Sphaleron

We present a self-consistent ansatz for a new sphaleron in the electroweak standard model. The resulting field equations are solved numerically. This sphaleron sets the height of the energy barrier for the global SU(2) anomaly.Comment: 13 pages, Latex, NIKHEF-H/93-09 (June 1993), postscript file including figures 1 and 2 available by anonymous ftp, figure 3 available by fax (send request to [email protected]

Solutions of the Bosonic Master-Field Equation from a Supersymmetric Matrix Model

It has been argued that the bosonic large-N master field of the IIB matrix model can give rise to an emergent classical spacetime. In a recent paper, we have obtained solutions of a simplified bosonic master-field equation from a related matrix model. In this simplified equation, the effects of dynamic fermions were removed. We now consider the full bosonic master-field equation from a related supersymmetric matrix model for dimensionality D = 3 and matrix size N = 3. In this last equation, the effects of dynamic fermions are included. With an explicit realization of the random constants entering this algebraic equation, we establish the existence of nontrivial solutions. The small matrix size, however, does not allow us to make a definitive statement as to the appearance of a diagonal/banddiagonal structure in the obtained matrices

A sphaleron for the non-Abelian anomaly

A self-consistent Ansatz for a new sphaleron of SU(3) Yang-Mills-Higgs theory is presented. With a single triplet of Weyl fermions added, there exists, most likely, one pair of fermion zero modes, which is known to give rise to the non-Abelian (Bardeen) anomaly as a Berry phase. The corresponding SU(3) gauge field configuration could take part in the nonperturbative dynamics of Quantum Chromodynamics.Comment: LaTeX with elsart.cls, 26 pages, v4: published versio

Photon decay in a CPT-violating extension of quantum electrodynamics

We consider the process of photon decay in quantum electrodynamics with a CPT-violating Chern-Simons-like term added to the action. For a simplified model with only the quadratic Maxwell and Chern-Simons-like terms and the quartic Euler-Heisenberg term, we obtain a nonvanishing probability for the decay of a particular photon state into three others.Comment: LaTeX with elsart.cls, 16 pages; v4: published versio

CPT anomaly: a rigorous result in four dimensions

The existence of a CPT anomaly is established for a particular four-dimensional Abelian lattice gauge theory with Ginsparg-Wilson fermions.Comment: LaTeX with elsart.cls, 24 pages, v3: published versio

Quantum Scattering Process and Information Transfer Out of a Black Hole

We calculate the probability amplitude for tree-level elastic electronmuon scattering in Minkowski spacetime with carefully prepared initial and final wave packets. The obtained nonzero amplitude implies a nonvanishing probability for detecting a recoil electron outside the light cone of the initial muon. Transposing this Minkowski-spacetime scattering result to a near-horizon spacetime region of a massive Schwarzschild black hole and referring to a previously proposed Gedankenexperiment, we conclude that, in principle, it is possible to have information transfer from inside the black-hole horizon to outside