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A Unifying Framework for Perturbative Exponential Factorizations
(MDPI, 2021-03-17)
We propose a framework where Fer and Wilcox expansions for the solution of differential
equations are derived from two particular choices for the initial transformation that seeds the product
expansion. In this scheme, ...
On Multi-Index Filtrations Associated to Weierstraß Semigroups
(Springer, Cham, 2020-05-14)
This paper is a survey on the main techniques involved in the computation of the Weierstraß semigroup at several points of curves defined over perfect fields, with special emphasis on the case of two points. Some hints ...
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 ...
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 ...
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 ...
A Modified SIRD Model to Study the Evolution of the COVID-19 Pandemic in Spain
(Multidisciplinary Digital Publishing Institute, 2021-04-19)
In this paper, we use an SIRD model to analyze the evolution of the COVID-19 pandemic in
Spain, caused by a new virus called SARS-CoV-2 from the coronavirus family. This model is governed
by a nonlinear system of ...
Composition Methods for Dynamical Systems Separable into Three Parts
(MDPI, 2020)
New families of fourth-order composition methods for the numerical integration of initial
value problems defined by ordinary differential equations are proposed. They are designed when
the problem can be separated into ...
The weak compactification of locally compact groups
(Elsevier, 2021)
We further investigate the weak topology generated by the irreducible unitary representations of a group G. A deep result due to Ernest [13] and Hughes [22] asserts that every weakly compact subset of a locally compact ...
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 ...
Homomorphic encoders of profinite abelian groups I
(Elsevier, 2023-05)
Let {Gi |i ∈ N} be a family of finite Abelian groups. We say that a subgroup
G ≤
i∈N
Gi is order controllable if for every i ∈ N there is ni ∈ N such that for
each c ∈ G, there exists a ∈ G satisfying that a|[1,i] = ...