2,075 research outputs found
Secular models and Kozai resonance for planets in coorbital non-coplanar motion
In this work, we construct and test an analytical and a semianalytical
secular models for two planets locked in a coorbital non-coplanar motion,
comparing some results with the case of restricted three body problem.
The analytical average model replicates the numerical N-body integrations,
even for moderate eccentricities ( 0.3) and inclinations
(), except for the regions corresponding to quasi-satellite
and Lidov-Kozai configurations. Furthermore, this model is also useful in the
restricted three body problem, assuming very low mass ratio between the
planets. We also describe a four-degree-of-freedom semianalytical model valid
for any type of coorbital configuration in a wide range of eccentricities and
inclinations.
{Using a N-body integrator, we have found that the phase space of the General
Three Body Problem is different to the restricted case for inclined systems,
and establish the location of the Lidov-Kozai equilibrium configurations
depending on mass ratio. We study the stability of periodic orbits in the
inclined systems, and find that apart from the robust configurations ,
, and is possible to harbour two Earth-like planets in orbits
previously identified as unstable and also in Euler configurations,
with bounded chaos.Comment: 15 pages. 20 figure
Algebra of chiral currents on the physical surface
Using a particular structure for the Lagrangian action in a one-dimensional
Thirring model and performing the Dirac's procedure, we are able to obtain the
algebra for chiral currents which is entirely defied on the constraint surface
in the corresponding hamiltonian description of the theory.Comment: 10 page
MAMA: An Algebraic Map for the Secular Dynamics of Planetesimals in Tight Binary Systems
We present an algebraic map (MAMA) for the dynamical and collisional
evolution of a planetesimal swarm orbiting the main star of a tight binary
system (TBS). The orbital evolution of each planetesimal is dictated by the
secular perturbations of the secondary star and gas drag due to interactions
with a protoplanetary disk. The gas disk is assumed eccentric with a constant
precession rate. Gravitational interactions between the planetesimals are
ignored. All bodies are assumed coplanar. A comparison with full N-body
simulations shows that the map is of the order of 100 times faster, while
preserving all the main characteristics of the full system.
In a second part of the work, we apply MAMA to the \gamma-Cephei, searching
for friendly scenarios that may explain the formation of the giant planet
detected in this system. For low-mass protoplanetary disks, we find that a
low-eccentricity static disk aligned with the binary yields impact velocities
between planetesimals below the disruption threshold. All other scenarios
appear hostile to planetary formation
Non-covalent interactions at electrochemical interfaces : one model fits all?
Acknowledgements Funding from the DGI (Spanish Ministry of Education and Science) through Project CTQ2009-07017 is gratefully acknowledged. E.P.M.L. wishes to thank the Universidad Nacional de Co´rdoba, Argentina, for a grant within the ‘‘Programa de Movilidad Internacional de Profesores Cuarto Centenario’’.Peer reviewedPublisher PD
2D-Drop model applied to the calculation of step formation energies on a (111) substrate
A model is presented for obtaining the step formation energy for metallic
islands on (111) surfaces from Monte Carlo simulations. This model is applied
to homo (Cu/Cu(111), Ag/Ag(111)) and heteroepitaxy (Ag/Pt(111)) systems. The
embedded atom method is used to represent the interaction between the particles
of the system, but any other type of potential could be used as well. The
formulation can also be employed to consider the case of other single crystal
surfaces, since the higher barriers for atom motion on other surfaces are not a
hindrance for the simulation scheme proposed.Comment: 12 pages, LaTeX2e, 2 included EPS figures, submitted to Surface
Science Subj-clas
Optimising Humanness: Designing the best human-like Bot for Unreal Tournament 2004
This paper presents multiple hybridizations of the two best
bots on the BotPrize 2014 competition, which sought for the best humanlike
bot playing the First Person Shooter game Unreal Tournament 2004.
To this aim the participants were evaluated using a Turing test in the
game. The work considers MirrorBot (the winner) and NizorBot (the
second) codes and combines them in two different approaches, aiming to
obtain a bot able to show the best behaviour overall. There is also an
evolutionary version on MirrorBot, which has been optimized by means
of a Genetic Algorithm. The new and the original bots have been tested
in a new, open, and public Turing test whose results show that the evolutionary
version of MirrorBot apparently improves the original bot, and
also that one of the novel approaches gets a good humanness level.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
The underpotential deposition that should not be : Cu(1x1) on Au(111)
Peer reviewedPostprin
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