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Roland E. Allen

Publications and source records attributed to Roland E. Allen.

32 records · Page 2Linked to original sources
arXiv2010

Supersymmetric SO(N) from a Planck-scale statistical theory

Several refinements are made in a theory which starts with a Planck-scale statistical picture and ends with supersymmetry and a coupling of fundamental fermions and bosons to SO(N) gauge fields. In particular, more satisfactory treatments are given for (1) the transformation from the initial Euclidean form of the path integral for fermionic fields to the usual Lorentzian form, (2) the corresponding transformation for bosonic fields (which is much less straightforward), (3) the transformation from an initial primitive supersymmetry to the final standard form (containing, e.g., scalar sfermions and their auxiliary fields), (4) the initial statistical picture, and (5) the transformation to an action which is invariant under general coordinate transformations.

hep-th↗
arXiv2008

Coupling of electrons to the electromagnetic field in a localized basis

A simple formula is obtained for coupling electrons in a complex system to the electromagnetic field. It includes the effect of intra-atomic excitations and nuclear motion, and can be applied in. e.g., first-principles-based simulations of the coupled dynamics of electrons and nuclei in materials and molecules responding to ultrashort laser pulses. Some additional aspects of nonadiabatic dynamical simulations are also discussed, including the potential of "reduced Ehrenfest'" simulations for treating problems where standard Ehrenfest simulations will fail.

quant-ph↗
arXiv2007

Standard supersymmetry from a Planck-scale statistical theory

We outline three new ideas in a program to obtain standard physics, including standard supersymmetry, from a Planck-scale statistical theory: (1) The initial spin 1/2 bosonic fields are transformed to spin 0 fields together with their auxiliary fields. (2) Time is defined by the progression of 3-geometries, just as originally proposed by DeWitt. (3) The initial (D-1)-dimensional "path integral" is converted from Euclidean to Lorentzian form by transformation of the fields in the integrand.

physics.gen-ph↗
arXiv2005

Sfermions and gauginos in a Lorentz-violating theory

In Lorentz-violating supergravity, sfermions have spin 1/2 and other unusual properties. If the dark matter consists of such particles, there is a natural explanation for the apparent absence of cusps and other small scale structure: The Lorentz-violating dark matter is cold because of the large particle mass, but still moves at nearly the speed of light. Although the R-parity of a sfermion, gaugino, or gravitino is +1 in the present theory, these particles have an "S-parity'' which implies that the LSP is stable and that they are produced in pairs. On the other hand, they can be clearly distinguished from the superpartners of standard supersymmetry by their highly unconventional properties.

hep-th↗
arXiv2004

Searching for Lorentz Violation

Astrophysical, terrestrial, and space-based searches for Lorentz violation are very briefly reviewed. Such searches are motivated by the fact that all superunified theories (and other theories that attempt to include quantum gravity) have some potential for observable violations of Lorentz invariance. Another motivation is the exquisite sensitivity of certain well-designed experiments and observations to particular forms of Lorentz violation. We also review some new predictions of a specific Lorentz-violating theory: If a fundamental energy \bar{m} in this theory lies below the usual GZK cutoff E_{GZK}, the cutoff is shifted to infinite energy; i.e., it no longer exists. On the other hand, if \bar{m} lies above E_{GZK}, there is a high-energy branch of the fermion dispersion relation which provides an alternative mechanism for super-GZK cosmic-ray protons.

hep-th↗
arXiv2003

Lorentz-Violating Supergravity

The standard forms of supersymmetry and supergravity are inextricably wedded to Lorentz invariance. Here a Lorentz-violating form of supergravity is proposed. The superpartners have exotic properties that are not possible in a theory with exact Lorentz symmetry and microcausality. For example, the bosonic sfermions have spin 1/2 and the fermionic gauginos have spin 1. The theory is based on a phenomenological action that is shown to follow from a simple microscopic and statistical picture.

hep-th↗
arXiv2002

Spin 1/2 bosons etc. in a theory with Lorentz violation

An action with unconventional supersymmetry was introduced in an earlier paper. Here it is shown that this action leads to standard physics for fermions and gauge bosons at low energy, but to testable extensions of standard physics for fermions at high energy and for fundamental bosons which have not yet been observed. For example, the Lorentz-violating equation of motion for these bosons implies that they have spin 1/2.

hep-th↗
arXiv2001

Dark Matter Equation of Motion and Density Profiles

Cold dark matter simulations appear to disagree with the observations on small distance scales. Here we consider a modified description of CDM particles which is implied by a new fundamental theory: In this picture, the dark matter is composed of supersymmetric WIMPs, but they are scalar bosons with an unconventional equation of motion. The modified dynamics leads to much weaker gravitational binding, and therefore to a reduced tendency to form small clumps and central cusps.

astro-ph↗
arXiv2000

The Higgs as a Supersymmetric Partner, with a New Interpretation of Yukawa Couplings

An unconventional version of supersymmetry leads to the following highly testable predictions: (1) The Higgs boson has an R-parity of -1, so it can only be produced as one member of a pair of superpartners. (2) The only superpartners are scalar bosons, so neutralinos etc. do not exist. (3) The most likely candidate for cold dark matter is therefore a sneutrino. (4) The Higgs and other bosonic superpartners have an unconventional equation of motion. These predictions are associated with new interpretations of Yukawa couplings, supersymmetry, gauge fields, and Lorentz invariance.

hep-ph↗
arXiv1999

New Physics Near 1 TeV and Above

A new theory makes testable predictions: (1) Higgs fields have an unconventional equation of motion. (2) Fermions have a second-order coupling to gauge fields. (3) Fermion propagators are modified at high energy. (4) There are new scalar bosons which are supersymmetric partners of spin 1/2 fermions. (5) Since W-bosons gravitate differently from fermions and massless gauge bosons, there is a very small violation of the equivalence principle. Other features of the theory have implications for cosmology, including the values of cosmological parameters, a mechanism for scale-invariant density fluctuations, and a candidate for dark matter.

hep-ph↗
arXiv1997

A statistical superfield and its observable consequences

A new kind of fundamental superfield is proposed, with an Ising-like Euclidean action. Near the Planck energy it undergoes its first stage of symmetry-breaking, and the ordered phase is assumed to support specific kinds of topological defects. This picture leads to a low-energy Lagrangian which is similar to that of standard physics, but there are interesting and observable differences. For example, the cosmological constant vanishes, fermions have an extra coupling to gravity, the gravitational interaction of W-bosons is modified, and Higgs bosons have an unconventional equation of motion.

hep-th↗