11,883 research outputs found
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
Information-Entropic Measure of Energy-Degenerate Kinks in Two-Field Models
We investigate the existence and properties of kink-like solitons in a class
of models with two interacting scalar fields. In particular, we focus on models
that display both double and single-kink solutions, treatable analytically
using the Bogomol'nyi--Prasad--Sommerfield bound (BPS). Such models are of
interest in applications that include Skyrmions and various
superstring-motivated theories. Exploring a region of parameter space where the
energy for very different spatially-bound configurations is degenerate, we show
that a newly-proposed momentum-space entropic measure called Configurational
Entropy (CE) can distinguish between such energy-degenerate spatial profiles.
This information-theoretic measure of spatial complexity provides a
complementary perspective to situations where strictly energy-based arguments
are inconclusive
Bounds on topological Abelian string-vortex and string-cigar from information-entropic measure
In this work we obtain bounds on the topological Abelian string-vortex and on
the string-cigar, by using a new measure of configurational complexity, known
as configurational entropy. In this way, the information-theoretical measure of
six-dimensional braneworlds scenarios are capable to probe situations where the
parameters responsible for the brane thickness are arbitrary. The so-called
configurational entropy (CE) selects the best value of the parameter in the
model. This is accomplished by minimizing the CE, namely, by selecting the most
appropriate parameters in the model that correspond to the most organized
system, based upon the Shannon information theory. This information-theoretical
measure of complexity provides a complementary perspective to situations where
strictly energy-based arguments are inconclusive. We show that the higher the
energy the higher the CE, what shows an important correlation between the
energy of the a localized field configuration and its associated entropic
measure.Comment: 6 pages, 7 figures, final version to appear in Phys. Lett.
Magnetic field induced lattice anomaly inside the superconducting state of CeCoIn: evidence of the proposed Fulde-Ferrell-Larkin-Ovchinnikov state
We report high magnetic field linear magnetostriction experiments on
CeCoIn single crystals. Two features are remarkable: (i) a sharp
discontinuity in all the crystallographic axes associated with the upper
superconducting critical field that becomes less pronounced as the
temperature increases; (ii) a distinctive second order-like feature observed
only along the c-axis in the high field (10 T ) low
temperature ( 0.35 K) region. This second order transition is
observed only when the magnetic field lies within 20 of the ab-planes and
there is no signature of it above , which raises questions regarding
its interpretation as a field induced magnetically ordered phase. Good
agreement with previous results suggests that this anomaly is related to the
transition to the Fulde-Ferrel-Larkin-Ovchinnikov superconducting state.Comment: 3 figures, 5 page
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