19 citations · 181 across the 33 of their papers we have counts for
35 papers
Optimization with inequality constraints by the embedded gradient vector field method
Petre Birtea, Ioan Casu, Dan Comanescu
We develop a geometric framework for constrained optimization problems with inequality constraints through the introduction of quadratic slack variables. This formulation makes it…
An explicit formula for the Laplace-Beltrami operator on the Stiefel manifold
Petre Birtea, Ioan Casu, Dan Comanescu
We derive an explicit formula for the Laplace-Beltrami operator on the orthogonal Stiefel manifold, viewed as a constraint submanifold of the Euclidean space of real matrices equip…
Upper block triangular form for the Laplace-Beltrami operator on the special orthogonal group acquired through a flag of trace polynomials spaces
Petre Birtea, Ioan Casu, Dan Comanescu
The Laplacian of a general trace polynomial function defined on the special orthogonal group is explicitly computed. An invariant flag of spaces generated by trace polynomi…
Generalized double bracket vector fields
Petre Birtea, Zohreh Ravanpak, Cornelia Vizman
We generalize double bracket vector fields, originally defined on semisimple Lie algebras, to Poisson manifolds equipped with a pseudo-Riemannian metric by utilizing a symmetric co…
Parametric Lie group structures on the probabilistic simplex and generalized Compositional Data
Petre Birtea, Ioana Gavra
In this paper we build a set of parametric quotient Lie group structures on the probabilistic simplex that can be extended to real vector space structures. In particular, we redisc…
Laplace-Beltrami operator on the orthogonal group in Cartesian coordinates
Petre Birtea, Ioan Casu, Dan Comanescu
Using the embedded gradient vector field method (see P. Birtea, D. Comanescu, Hessian operators on constraint manifolds, J. Nonlinear Science 25, 2015), we present a general formul…