‎we characterize those groups $g$ and vector spaces $v$ such that $v$ is a faithful irreducible $g$-module and such that each $v$ in $v$ is centralized by a $g$-conjugate of a fixed non-identity element of the fitting subgroup $f(g)$ of $g$‎. ‎we also determine those $v$ and $g$ for which $v$ is a faithful quasi-primitive $g$-module and $f(g)$ has no regular orbit‎. ‎we do use these to show in ...

The common belief that the CMB is Gaussian distributed can be directly traced back to the generic assumption that the quantum fluctuations of the inflaton field are placed in the vacuum state 1. Relaxing this assumption might lead to detectable signatures in various astrophysical tests, most interestingly in future CMB and large-scale structure observations. In this note, we study CMB non-Gauss...

Cross-correlations between Cosmic Microwave Background (CMB) temperature and polarization anisotropies $\mu$-spectral distortions have been considered to measure (squeezed) primordial scalar bispectra in a range of scales inaccessible primary CMB bispectra. In this work we address whether it is possible constrain tensor non-Gaussianities with these cross-correlations. We find that only statisti...

the paper is concerned with the bifurcation of limit cycles in general quadratic perturbations of a quadratic reversible and non-hamiltonian system, whose period annulus is bounded by an elliptic separatrix related to a singularity at infinity in the poincar'{e} disk. attention goes to the number of limit cycles produced by the period annulus under perturbations. by using the appropriate p...

We provide an effective uniform upper bond for the number of zeros of the first non-vanishing Melnikov function of a polynomial perturbations of a planar polynomial Hamiltonian vector field. The bound depends on degrees of the field and of the perturbation, and on the order k of the Melnikov function. The generic case k = 1 was considered by Binyamini, Novikov and Yakovenko ( [BNY10]). The boun...

A closed formula for ultimate bound estimation in LTI systems with non–vanishing perturbations is presented. The formula, based on geometrical properties of the system, provides an alternative to Lyapunov’s second method based study. Although it is not proven that the bound obtained is always less conservative than the Lyapunov’s bound, some examples are introduced where the estimations are sig...

We have obtained the Generalized Uncertainty Principle (GUP) corrected de Sitter and anti-de black hole solutions in bumblebee gravity with a topological defect. calculated scalar, electromagnetic gravitational quasinormal modes for both vanishing non-vanishing effective cosmological constant using Pad\'e averaged sixth order WKB approximation method. Apart from this, time evolutions all three ...

We present a stability result for a class of non-trivial self-similarly vanishing solutions to a 3D Hele-Shaw moving boundary problem with surface tension and single-point suction. These solutions are domains that bifurcate from the trivial spherical solution. The moving domains have a geometric centre located at the suction point and they are axially symmetric. We show stability with respect t...

We prove a continuity inheritance property for super- and sub-additive transformations of non-negative continuous multivariate functions defined on the domain of all non-negative points and vanishing at the origin. As a corollary of this result we obtain that super- and sub-additive transformations of continuous aggregation functions are again continuous aggregation functions.