Implications of quaternionic dark matter

Taking the complex nature of quantum mechanics which we observe today as a low energy effect of a broken quaternionic theory we explore the possibility that dark matter arises as a consequence of this underlying quaternionic structure to our universe. We introduce a low energy, effective, Lagrangian which incorporates the remnants of a local quaternionic algebra, investigate the stellar production of the resultant exotic bosons and explore the possible low energy consequences of our remnant extended Hilbert space.Comment: 14 pages, RevTeX, no figure

Experimental status of quaternionic quantum mechanics

Analysis of the logical foundations of quantum mechanics indicates the possibility of constructing a theory using quaternionic Hilbert spaces. Whether this mathematical structure reflects reality is a matter for experiment to decide. We review the only direct search for quaternionic quantum mechanics yet carried out and outline a recent proposal by the present authors to look for quaternionic effects in correlated multi-particle systems. We set out how such experiments might distinguish between the several quaternionic models proposed in the literature.Comment: 8 pages, no figures, revtex. An update of paper appearing in journal reference given below, with minor amendments and latest additional reference

Field on Poincare group and quantum description of orientable objects

We propose an approach to the quantum-mechanical description of relativistic orientable objects. It generalizes Wigner's ideas concerning the treatment of nonrelativistic orientable objects (in particular, a nonrelativistic rotator) with the help of two reference frames (space-fixed and body-fixed). A technical realization of this generalization (for instance, in 3+1 dimensions) amounts to introducing wave functions that depend on elements of the Poincare group $G$. A complete set of transformations that test the symmetries of an orientable object and of the embedding space belongs to the group $\Pi =G\times G$. All such transformations can be studied by considering a generalized regular representation of $G$ in the space of scalar functions on the group, $f(x,z)$, that depend on the Minkowski space points $x\in G/Spin(3,1)$ as well as on the orientation variables given by the elements $z$ of a matrix $Z\in Spin(3,1)$. In particular, the field $f(x,z)$ is a generating function of usual spin-tensor multicomponent fields. In the theory under consideration, there are four different types of spinors, and an orientable object is characterized by ten quantum numbers. We study the corresponding relativistic wave equations and their symmetry properties.Comment: 46 page

Superconductivity from doping a spin liquid insulator: a simple one-dimensional example

We study the phase diagram of a one-dimensional Hubbard model where, in addition to the standard nearest neighbor hopping $t$, we also include a next-to-nearest neighbor hopping $t'$. For strong enough on-site repulsion, this model has a transition at half filling from a magnetic insulator with gapless spin excitations at small $t'/t$ to a dimerized insulator with a spin gap at larger $t'/t$. We show that upon doping this model exhibits quite interesting features, which include the presence of a metallic phase with a spin gap and dominant superconducting fluctuations, in spite of the repulsive interaction. More interestingly, we find that this superconducting phase can be reached upon hole doping the magnetic insulator. The connections between this model and the two chain models, recently object of intensive investigations, are also discussed.Comment: 19 pages, plain LaTex using RevTex, 7 postscript figures Modified version which excludes some LaTex commands giving problems for the previous versio

The 3D Structure of N132D in the LMC: A Late-Stage Young Supernova Remnant

We have used the Wide Field Spectrograph (WiFeS) on the 2.3m telescope at Siding Spring Observatory to map the [O III] 5007{\AA} dynamics of the young oxygen-rich supernova remnant N132D in the Large Magellanic Cloud. From the resultant data cube, we have been able to reconstruct the full 3D structure of the system of [O III] filaments. The majority of the ejecta form a ring of ~12pc in diameter inclined at an angle of 25 degrees to the line of sight. We conclude that SNR N132D is approaching the end of the reverse shock phase before entering the fully thermalized Sedov phase of evolution. We speculate that the ring of oxygen-rich material comes from ejecta in the equatorial plane of a bipolar explosion, and that the overall shape of the SNR is strongly influenced by the pre-supernova mass loss from the progenitor star. We find tantalizing evidence of a polar jet associated with a very fast oxygen-rich knot, and clear evidence that the central star has interacted with one or more dense clouds in the surrounding ISM.Comment: Accepted for Publication in Astrophysics & Space Science, 18pp, 8 figure

Treasurehunt: Transients and variability discovered with HST in the JWST North Ecliptic Pole time-domain field

The James Webb Space Telescope (JWST) North Ecliptic Pole (NEP) Time-domain Field (TDF) is a >14' diameter field optimized for multiwavelength time-domain science with JWST. It has been observed across the electromagnetic spectrum both from the ground and from space, including with the Hubble Space Telescope (HST). As part of HST observations over three cycles (the "TREASUREHUNT" program), deep images were obtained with the Wide Field Camera on the Advanced Camera for Surveys in F435W and F606W that cover almost the entire JWST NEP TDF. Many of the individual pointings of these programs partially overlap, allowing an initial assessment of the potential of this field for time-domain science with HST and JWST. The cumulative area of overlapping pointings is ∼88 arcmin2, with time intervals between individual epochs that range between 1 day and 4+ yr. To a depth of mAB ≃ 29.5 mag (F606W), we present the discovery of 12 transients and 190 variable candidates. For the variable candidates, we demonstrate that Gaussian statistics are applicable and estimate that ∼80 are false positives. The majority of the transients will be supernovae, although at least two are likely quasars. Most variable candidates are active galactic nuclei (AGNs), where we find 0.42% of the general z ≲ 6 field galaxy population to vary at the ∼3σ level. Based on a 5 yr time frame, this translates into a random supernova areal density of up to ∼0.07 transients arcmin−2 (∼245 deg−2) per epoch and a variable AGN areal density of ∼1.25 variables arcmin−2 (∼4500 deg−2) to these depths

Homocysteine and its disulfide derivatives: a suggested consensus terminology.

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