56 citations · 280 across the 32 of their papers we have counts for
32 papers
From Holst to Carroll Gravity, a Hamiltonian point of view
J. Fernando Barbero G, Juan Margalef-Bentabol, Valle Varo +1
The Carrollian regime of gravity provides a useful ultrarelativistic framework for studying asymptotically flat spacetimes, horizon dynamics, and condensed matter systems. In this…
xCPS: an xAct package for covariant phase space, Noether charges, and entropy
Juan Margalef-Bentabol
xCPS is an xAct tensor algebra package for symbolic computations within the covariant phase space formalism of field theories. From a generic Lagrangian, xCPS automates the derivat…
Husain-Kuchař model as the Carrollian limit of the Holst term
J. Fernando Barbero G., Juan Margalef-Bentabol, Aitor Vicente-Cano +1
We show how the Husain-Kuchař model can be understood as a Carrollian limit of the Holst term in the context of background-independent field theories described in terms of coframes…
Hidden diffeos in the Hamiltonian formulation of a background independent field theory
J. Fernando Barbero G., Bogar Díaz, Juan Margalef-Bentabol +1
We analyze from a geometric perspective the Hamiltonian formulation of a recent modification of the Husain-Kuchař model where, while preserving the connection as a dynamical variab…
Dynamical time and Ashtekar variables for the Husain-Kuchař model
J. Fernando Barbero G., Juan Margalef-Bentabol, Aitor Vicente-Cano +1
The relation between the Husain-Kuchař model and some extensions thereof that incorporate a dynamical time variable is explored. To this end, we rely on the geometric approach to t…
The Penrose inequality in spherical symmetry with charge and in Gauss-Bonnet gravity
Hari K. Kunduri, Juan Margalef-Bentabol, Sarah Muth
We establish the spacetime Penrose inequality in spherical symmetry in spacetime dimensions with charge and cosmological constant from the initial data perspective. We a…
Symmetry and instability of marginally outer trapped surfaces
Ivan Booth, Graham Cox, Juan Margalef-Bentabol
We consider an initial data set having a continuous symmetry and a marginally outer trapped surface (MOTS) that is not preserved by this symmetry. We show that such a MOTS is unsta…
What is a degree of freedom? Configuration spaces and their topology
Juan Margalef-Bentabol, Leigh Herman, Ivan Booth
Understanding degrees of freedom in classical mechanics is fundamental to characterizing physical systems. Counting them is usually easy, especially if we can assign them a clear m…
Proof of the equivalence of the symplectic forms derived from the canonical and the covariant phase space formalisms
Juan Margalef-Bentabol, Eduardo J. S. Villaseñor
We prove that, for any theory defined over a space-time with boundary, the symplectic form derived in the covariant phase space is equivalent to the one derived from the canonical…
Edge observables of the Maxwell-Chern-Simons theory
J. Fernando Barbero G., Bogar Díaz, Juan Margalef-Bentabol +1
We analyze the Lagrangian and Hamiltonian formulations of the Maxwell-Chern-Simons theory defined on a manifold with boundary for two different sets of boundary equations derived f…
On the on-shell equivalence of general relativity and Holst theories with nonmetricity, torsion, and boundaries
J. Fernando Barbero G., Juan Margalef-Bentabol, Valle Varo +1
We study a generalization of the Holst action where we admit nonmetricity and torsion in manifolds with timelike boundaries (both in the metric and tetrad formalism). We prove that…
Palatini gravity with nonmetricity, torsion, and boundaries in metric and connection variables
Fernando Barbero G., Juan Margalef-Bentabol, Valle Varo +1
We prove the equivalence in the covariant phase space of the metric and connection formulations for Palatini gravity, with nonmetricity and torsion, on a spacetime manifold with bo…
Covariant phase space for gravity with boundaries: metric vs tetrad formulations
J. Fernando Barbero G., Juan Margalef-Bentabol, Valle Varo +1
We use covariant phase space methods to study the metric and tetrad formulations of General Relativity in a manifold with boundary and compare the results obtained in both approach…
Hamiltonian Gotay-Nester-Hinds analysis of the parametrized unimodular extension of the Holst action
J. Fernando Barbero G., Bogar Díaz, Juan Margalef-Bentabol +1
We give a detailed account of the Hamiltonian GNH analysis of the parametrized unimodular extension of the Holst action. The purpose of the paper is to derive, through the clear ge…
Concise symplectic formulation for tetrad gravity
J. Fernando Barbero G., Bogar Díaz, Juan Margalef-Bentabol +1
We discuss a simple symplectic formulation for tetrad gravity that leads to the real Ashtekar variables in a direct and transparent way. It also sheds light on the role of the Immi…
Geometric formulation of the Covariant Phase Space methods with boundaries
Juan Margalef-Bentabol, Eduardo J. S. Villaseñor
We analyze in full-detail the geometric structure of the covariant phase space (CPS) of any local field theory defined over a space-time with boundary. To this end, we introduce a…
A two-sided Faulhaber-like formula involving Bernoulli polynomials
Fernando Barbero G., Juan Margalef-Bentabol, Eduardo J. S. Villaseñor
We give a new identity involving Bernoulli polynomials and combinatorial numbers. This provides, in particular, a Faulhaber-like formula for sums of the form $1^m (n-1)^m + 2^m (n-…
Generalizations of the Pontryagin and Husain-Kuchař actions to manifolds with boundary
J. Fernando Barbero G., Bogar Díaz, Juan Margalef-Bentabol +1
In this paper we study a family of generalizations of the Pontryagin and Husain-Kuchař actions on manifolds with boundary. In some cases, they describe well-known models---either a…
Dirac's algorithm in the presence of boundaries: a practical guide to a geometric approach
J. Fernando Barbero G., Bogar Díaz, Juan Margalef-Bentabol +1
The goal of this paper is to propose and discuss a practical way to implement the Dirac algorithm for constrained field models defined on spatial regions with boundaries. Our metho…
Towards general relativity through parametrized theories
Juan Margalef-Bentabol
Boundaries, GNH, and parametrized theories. It takes three to tango. This is the motto of my doctoral thesis and the common thread of it. The thesis is structured as follows: after…
On the distribution of the eigenvalues of the area operator in loop quantum gravity
J. Fernando Barbero, Juan Margalef-Bentabol, Eduardo J. S. Villaseñor
We study the distribution of the eigenvalues of the area operator in loop quantum gravity concentrating on the part of the spectrum relevant for isolated horizons. We first show th…
Boundary Hilbert spaces and trace operators
J. Fernando G. Barbero, Benito A. Juárez-Aubry, Juan Margalef-Bentabol +1
We discuss the introduction of boundary Hilbert spaces for a class of physical systems for which it is not possible to factor their state spaces as tensor products of Hilbert space…
Functional evolution of scalar fields in bounded one-dimensional regions
J. Fernando G. Barbero, Juan Margalef-Bentabol, Eduardo J. S. Villaseñor
We discuss the unitarity of the quantum evolution between arbitrary Cauchy surfaces of a 1+1 dimensional free scalar field defined on a bounded spatial region and subject to severa…
Hamiltonian dynamics of the parametrized electromagnetic field
J. Fernando Barbero, Juan Margalef-Bentabol, Eduardo J. S. Villaseñor
We study the Hamiltonian formulation for a parametrized electromagnetic field with the purpose of clarifying the interplay between parametrization and gauge symmetries. We use a ge…