6,789 research outputs found
MHD Remote Numerical Simulations: Evolution of Coronal Mass Ejections
Coronal mass ejections (CMEs) are solar eruptions into interplanetary space
of as much as a few billion tons of plasma, with embedded magnetic fields from
the Sun's corona. These perturbations play a very important role in
solar--terrestrial relations, in particular in the spaceweather. In this work
we present some preliminary results of the software development at the
Universidad Nacional Autonoma de Mexico to perform Remote MHD Numerical
Simulations. This is done to study the evolution of the CMEs in the
interplanetary medium through a Web-based interface and the results are store
into a database. The new astrophysical computational tool is called the Mexican
Virtual Solar Observatory (MVSO) and is aimed to create theoretical models that
may be helpful in the interpretation of observational solar data.Comment: 2 pages, 1 color figure. To appear in Proceedings IAU Symposium No.
259. Cosmic Magnetic Fields: From Planets, to Stars and Galaxies. In pres
The quantum chiral Minkowski and conformal superspaces
We give a quantum deformation of the chiral super Minkowski space in four
dimensions as the big cell inside a quantum super Grassmannian. The
quantization is performed in such way that the actions of the Poincar\'e and
conformal quantum supergroups on the quantum Minkowski and quantum conformal
superspaces are presented.Comment: 54 page
Quadratic deformation of Minkowski space
We present a deformation of the Minkowski space as embedded into the
conformal space (in the formalism of twistors) based in the quantum versions of
the corresponding kinematic groups. We compute explicitly the star product,
whose Poisson bracket is quadratic. We show that the star product although
defined on the polynomials can be extended differentiably. Finally we compute
the Eucliden and Minkowskian real forms of the deformation.Comment: Presented at XVII European Workshop on String Theory 2011. Padova
(Italy) September 05-09; Fortschr. Phys. 1-7 (2012
Cosmological simulations using a static scalar-tensor theory
We present CDM -body cosmological simulations in the framework of
a static general scalar-tensor theory of gravity. Due to the influence of the
non-minimally coupled scalar field, the gravitational potential is modified by
a Yukawa type term, yielding a new structure formation dynamics. We present
some preliminary results and, in particular, we compute the density and
velocity profiles of the most massive group.Comment: 4 pages, 6 figures, to appear in Journal of Physics: Conference
Series: VII Mexican School on Gravitation and Mathematical Physics. 26
November to 1 December 2006, Playa del Carmen, Quintana Roo, Mexic
Ermakov Systems with Multiplicative Noise
Using the Euler-Maruyama numerical method, we present calculations of the
Ermakov-Lewis invariant and the dynamic, geometric, and total phases for
several cases of stochastic parametric oscillators, including the simplest case
of the stochastic harmonic oscillator. The results are compared with the
corresponding numerical noiseless cases to evaluate the effect of the noise.
Besides, the noiseless cases are analytic and their analytic solutions are
briefly presented. The Ermakov-Lewis invariant is not affected by the
multiplicative noise in the three particular examples presented in this work,
whereas there is a shift effect in the case of the phasesComment: 12 pages, 4 figures, 22 reference
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