Cerca
Invertibles in topological rings: a new approach
(Springer, 2021-11-15)
Every element in the boundary of the group of invertibles of a Banach algebra is a topological zero divisor. We extend this result to the scope of topological rings. In particular, we
define a new class of semi-normed ...
The Bishop-Phelps-Bollobás properties in complex Hilbert space
(Wiley, 2021-12-02)
In this paper, we consider theBishop–Phelps–Bollobás point propertyfor variousclasses of operators on complex Hilbert spaces, which is a stronger property thanthe Bishop–Phelps–Bollobás property. We also deal with analogous ...
Completeness of Hutton [0,1]-quasi-uniformities induced by a crisp uniformity
(University of Sistan and Baluchestan, 2019)
In [25], Katsaras introduced a method for constructing a Hutton [0,1]-quasi-uniformity from a crisp uniformity. In thispaper we present other different methods for making this based mainly in the concept of a fuzzy uniform ...
Applying splitting methods with complex coefficients to the numerical integration of unitary problems
(American Institute of Mathematical Sciences (AIMS), 2022)
We explore the applicability of splitting methods involving complex coefficients to solve numerically the time-dependent Schr¨odinger equation.
We prove that a particular class of integrators are conjugate to unitary ...
Connectivity of the Julia set for the Chebyshev-Halley family on degree n polynomials
(Elsevier, 2020-03)
We study the Chebyshev-Halley family of root finding algorithms from the point of view of holomorphic dynamics. Numerical experiments show that the speed of convergence to the roots may be slower when the basins of attraction ...
Runge–Kutta–Nyström symplectic splitting methods of order 8
(Elsevier, 2022-12)
Different families of Runge–Kutta–Nyström (RKN) symplectic splitting methods of order 8 are presented for second-order systems of ordinary differential equations and are tested on numerical examples. They show a better ...
Symplectic propagators for the Kepler problem with time-dependent mass
(Springer, 2019-06)
New numerical integrators specifically designed for solving the two-body gravitational problem with a time-varying mass are presented. They can be seen as a generalization of commutator-free quasi-Magnus exponential ...
Continuous changes of variables and the Magnus expansion
(IOP, 2019-09-23)
In this paper, we are concerned with a formulation of Magnus and Floquet-Magnus expansions for general nonlinear differential equations. To this aim, we introduce suitable continuous variable transformations generated by ...
Highly tempering infinite matrices
(Springer Milan, 2017-02)
In this short note, it is proved the existence of in nite matrices that
not only preserve convergence and limits of sequences but also convert every mem-
ber of some dense vector space consisting, except for zero, of ...
Foliations with isolated singularities on Hirzebruch surfaces
(De Gruyter, 2021)
We study foliations ℱ on Hirzebruch surfaces Sδ and prove that, similarly to those on the projective plane, any ℱ can be represented by a bi-homogeneous polynomial affine 1-form. In case ℱ has isolated singularities, we ...