100,471 research outputs found
Angular momentum I ground state probabilities of boson systems interacting by random interactions
In this paper we report our systematic calculations of angular momentum
ground state probabilities () of boson systems with spin in the
presence of random two-body interactions. It is found that the P(0) dominance
is usually not true for a system with an odd number of bosons, while it is
valid for an even number of bosons, which indicates that the P(0) dominance is
partly connected to the even number of identical particles. It is also noticed
that the 's of bosons with spin do not follow the 1/N (,
referring to the number of independent two-body matrix elements) relation. The
properties of the 's obtained in boson systems with spin are
discussed.Comment: 8 pages and 3 figure
An ecological approach to problems of Dark Energy, Dark Matter, MOND and Neutrinos
Modern astronomical data on galaxy and cosmological scales have revealed
powerfully the existence of certain dark sectors of fundamental physics, i.e.,
existence of particles and fields outside the standard models and inaccessible
by current experiments. Various approaches are taken to modify/extend the
standard models. Generic theories introduce multiple de-coupled fields A, B, C,
each responsible for the effects of DM (cold supersymmetric particles), DE
(Dark Energy) effect, and MG (Modified Gravity) effect respectively. Some
theories use adopt vanilla combinations like AB, BC, or CA, and assume A, B, C
belong to decoupled sectors of physics. MOND-like MG and Cold DM are often
taken as opposite frameworks, e.g. in the debate around the Bullet Cluster.
Here we argue that these ad hoc divisions of sectors miss important clues from
the data. The data actually suggest that the physics of all dark sectors is
likely linked together by a self-interacting oscillating field, which governs a
chameleon-like dark fluid, appearing as DM, DE and MG in different settings. It
is timely to consider an interdisciplinary approach across all semantic
boundaries of dark sectors, treating the dark stress as one identity, hence
accounts for several "coincidences" naturally.Comment: 12p, Proceedings to the 6-th Int. Conf. of Gravitation and Cosmology.
Neutrino section expande
A Radial Velocity Survey for LMC Microlensed Sources
We propose a radial velocity survey with the aim to resolve the current
dispute on the LMC lensing: in the pro-macho hypothesis the lenses are halo
white dwarfs or machos in general; in the pro-star hypothesis both the lenses
and the sources are stars in various observed or hypothesized structures of the
Magellanic Clouds and the Galaxy. Star-star lensing should prefer sources at
the backside or behind the LMC disc because lensing is most efficient if the
source is located a few kpc behind a dense screen of stars, here the thin disc
of the LMC. This signature of self-lensing can be looked for by a radial
velocity survey since kinematics of the stars at the back can be markedly
different from that of the majority of stars in the cold, rapidly rotating disc
of the LMC. Detailed simulations of effect together with optimal strategies of
carrying out the proposed survey are reported here. Assuming that the existing
30 or so alerted stars in the LMC are truely microlensed stars, their
kinematics can test the two lensing scenarios; the confidence level varies with
the still very uncertain structure of the LMC. Spectroscopy of the existing
sample and future events requires about two or three good-seeing nights per
year at a 4m-8m class southern telescope, either during the amplification phase
or long after.Comment: minor changes of text, ApJ accepte
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