1.2k citations · 1.9k across the 40 of their papers we have counts for
41 papers
Error bounds for the truncated Baker--Campbell--Hausdorff and Zassenhaus formulas in unitary problems
A. Arnal, F. Casas, J. L. Ruiz-Benito
The Baker--Campbell--Hausdorff (BCH) formula plays a critical role in many branches of mathematics and physics. It expresses the logarithm of the product of exponentials of non-com…
Approximating exponentials of commutators by optimized product formulas
F. Casas, A. Escorihuela-Tomàs, P. A. Moreno Casares
Trotter product formulas constitute a cornerstone quantum Hamiltonian simulation technique. However, the efficient implementation of Hamiltonian evolution of nested commutators rem…
Exponential perturbative expansions and coordinate transformations
Ana Arnal, Fernando Casas, Cristina Chiralt
We propose a unified approach for different exponential perturbation techniques used in the treatment of time-dependent quantum mechanical problems, namely the Magnus expansion, th…
A unifying framework for perturbative exponential factorizations
Ana Arnal, Fernando Casas, Cristina Chiralt
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…
Symmetric-conjugate splitting methods for linear unitary problems
Joackim Bernier, Sergio Blanes, Fernando Casas +1
We analyze the preservation properties of a family of reversible splitting methods when they are applied to the numerical time integration of linear differential equations defined…
A New Optimality Property of Strang's Splitting
Fernando Casas, Jesús María Sanz-Serna, Luke Shaw
For systems of the form , , common in many applications, we analyze splitting integrators based on the (linear/nonlinear) split systems $\dot…