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Nonmodal linear stability of the Schwarzschild black hole
(2014)
A proof is given that the space L of solutions of the linearized vacuum Einstein equation around a Schwarzschild black hole is parametrized by two scalar fields, which are gauge invariant combinations of perturbed algebraic ...
On nonsingular two-step nilpotent Lie algebras
(2014)
A 2-step nilpotent Lie algebra n is called non-singular if ad X : n → [n, n] is onto for any X /∈ [n, n]. We explore non-singular algebras in several directions, including the classification problem (isomorphism invariants), ...
The cohomology of filiform Lie algebras of maximal rank
(2014)
We describe the structure of the cohomology of the filiform Lie algebras and as a module over their (2-dimensional) torus of derivations. Our approach relies on the fact that both filiform algebras have an ideal of codimension ...
On homogeneous Ricci solitons
(2014)
We study the evolution of homogeneous Ricci solitons under the bracket flow, a dynamical system on the space Hq,n ⊂ Λ2g∗ ⊗ g of all homogeneous spaces of dimension n with a q-dimensional isotropy, which is equivalent to ...
Inequality between size and angular momentum for bodies
(2014-01-31)
A universal inequality that bounds the angular momentum of a body by the square of its size is presented
and heuristic physical arguments are given to support it. We prove a version of this inequality, as
consequence of ...
On the evolution of the momentarily static radiation free data in the Apostolatos - Thorne cylindrical shell model
(2014-02-24)
In this paper we study the evolution of the 'Momentarily Static and Radiation Free' (MSRF) initial data for the Apostolatos–Thorne cylindrical shell model. After briefly reviewing the equations of motion, the definition ...
Permutation entropy applied to the characterization of the clinical evolution of epileptic patients under pharmacological treatment
(2014)
Different techniques originated in information theory and tools from nonlinear systems theory have been applied to the analysis of electro-physiological time series. Several clinically relevant results have emerged from ...
Invertible bimodule categories over the representation category of a Hopf algebra
(2014-02-12)
For any finite-dimensional Hopf algebra H we construct a group homomorphism
BiGal (H) → BrPic(Rep(H)), from the group of equivalence classes of H-biGalois
objects to the group of equivalence classes of invertible exact ...
Water and membrane dynamics in suspensions of lipid vesicles functionalized with poly(ethylene glycol)s
(2014-05-08)
The present work was aimed at studying the molecular dynamics at different levels of model membranes having a simulated glycoclix, with focus on the molecular crowding conditions at the lipid–water interfacial region. Thus, ...
The growth of ice particles in a mixed phase environment based on laboratory observations
(2014)
This paper describes new laboratory observations about the size evolution of ice crystals and cloud droplets immersed in a mixed-phase cloud. The experiments were performed by using a cloud chamber facility for three ...