4,276 research outputs found
Scalar-tensor cosmological simulations
We present -body cosmlogical simulations in the framework of the Newtonian
limit of scalar-tensor theories of gravity. The scalar field is described by a
modified Helmholtz equation with a source that is coupled to the standard
Poisson equation of Newtonian gravity. The effective gravitational force is
given by two contributions: the standard Newtonian potential plus a Yukawa
potential stemming from massive scalar fields. In particular, we consider
simulations of CDM models and compute the density and velocity
profiles of the most massive groups found at z=0.Comment: 6 pages, 6 figures. Recent Developments in Gravitation and
Experimental Physics: 3rd Mexican Meeting of Mathematical and Experimental
Physics. Edited by A. Macias, C. Laemmerzahl, and A. Camacho. (American
Institute of Physics, 2008). Pag. 30
Latin American accounting research in extra-regional journals
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Highlighting the Disconnect Between Legislation and Sustainable Cannabis
Current legislation takes little regard for two major issues challenging the cannabis industry. The carbon footprint and legislation of cannabis are looked at where it is realized that neither is currently sustainable long-term. Solutions that require social responsibility from the legislation to preserve the culture and industry are delved into
Bayesian blind component separation for Cosmic Microwave Background observations
We present a technique for the blind separation of components in CMB data.
The method uses a spectral EM algorithm which recovers simultaneously component
templates, their emission law as a function of wavelength, and noise levels. We
test the method on Planck HFI simulated observations featuring 3 astrophysical
components.Comment: 15 pages, 5 figures, to appear in the Proceedings of the MAXENT 2001
international worksho
QFT results for neutrino oscillations and New Physics
The CP asymmetry in neutrino oscillations, assuming new physics at production
and/or detection processes, is analyzed. We compute this CP asymmetry using the
standard quantum field theory within a general new physics scenario that may
generate new sources of CP and flavor violation. Well known results for the CP
asymmetry are reproduced in the case of V -A operators, and additional
contributions from new physics operators are derived. We apply this formalism
to SUSY extensions of the Standard Model where the contributions from new
operators could produce a CP asymmetry observable in the next generation of
neutrino experiments.Comment: 6 pages, 3 figures, version to be published in Phys.Rev.
Limits to differences in active and passive charges
We explore consequences of a hypothetical difference between active charges,
which generate electric fields, and passive charges, which respond to them. A
confrontation to experiments using atoms, molecules, or macroscopic matter
yields limits on their fractional difference at levels down to 10^-21, which at
the same time corresponds to an experimental confirmation of Newtons third law.Comment: 6 pages Revtex. To appear in Phys. Rev.
Sensitivity of the Cherenkov Telescope Array to TeV photon emission from the Large Magellanic Cloud
A deep survey of the Large Magellanic Cloud at ∼0.1–100 TeV photon energies with the Cherenkov Telescope Array is planned. We assess the detection prospects based on a model for the emission of the galaxy, comprising the four known TeV emitters, mock populations of sources, and interstellar emission on galactic scales. We also assess the detectability of 30 Doradus and SN 1987A, and the constraints that can be derived on the nature of dark matter. The survey will allow for fine spectral studies of N 157B, N 132D, LMC P3, and 30 Doradus C, and half a dozen other sources should be revealed, mainly pulsar-powered objects. The remnant from SN 1987A could be detected if it produces cosmic-ray nuclei with a flat power-law spectrum at high energies, or with a steeper index 2.3–2.4 pending a flux increase by a factor of >3–4 over ∼2015–2035. Large-scale interstellar emission remains mostly out of reach of the survey if its >10 GeV spectrum has a soft photon index ∼2.7, but degree-scale 0.1–10 TeV pion-decay emission could be detected if the cosmic-ray spectrum hardens above >100 GeV. The 30 Doradus star-forming region is detectable if acceleration efficiency is on the order of 1−10 per cent of the mechanical luminosity and diffusion is suppressed by two orders of magnitude within <100 pc. Finally, the survey could probe the canonical velocity-averaged cross-section for self-annihilation of weakly interacting massive particles for cuspy Navarro–Frenk–White profiles
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