4,075 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.
HCV epidemiology in high-risk groups and the risk of reinfection
Injecting risk behaviours among people who inject drugs (PWID) and high-risk sexual practices among men who have sex with men (MSM) are important routes of hepatitis C virus (HCV) transmission. Current direct-acting antiviral treatment offers unique opportunities for reductions in HCV-related liver disease burden and epidemic control in high-risk groups, but these prospects could be counteracted by HCV reinfection due to on-going risk behaviours after successful treatment. Based on existing data from small and heterogeneous studies of interferon-based treatment, the incidence of reinfection after sustained virological response range from 2-6/100 person years among PWID to 10-15/100 person years among human immunodeficiency virus-infected MSM. These differences mainly reflect heterogeneity in study populations with regards to risk behaviours, but also reflect variations in study designs and applied virological methods. Increasing levels of reinfection are to be expected as we enter the interferon-free treatment era. Individual- and population-level efforts to address and prevent reinfection should therefore be undertaken when providing HCV care for people with on-going risk behaviour. Constructive strategies include acknowledgement, education and counselling, harm reduction optimization, scaled-up treatment including treatment of injecting networks, post-treatment screening, and rapid retreatment of reinfections
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