48 citations · 107 across the 34 of their papers we have counts for
35 papers
Generalized Kerr-Schild gauge
Enrique Alvarez, Jesus Anero
The Kerr-Schild gauge is generalized to the case that the vector generating the deformation is not null. Contrary to naive expectations, this vector generates a finite expansion fo…
On the Weyl anomaly for chiral fermions
Enrique Alvarez, Luis Alvarez-Gaume, Jesus Anero +1
We compute the parity-odd part of the Weyl anomaly for chiral fermions in a background gravitational field. We start from a manifestly real form of the Lagrangian (that is, not onl…
One loop analysis of the cubic action for gravity
Enrique Alvarez, Jesus Anero, Carmelo P. Martin
We analyze some aspects of the cubic action for gravity recently proposed by Cheung and Remmen, which is a particular instance of a first order (Palatini) action. In this approach…
Some aspects of QFT in non-inertial frames
Enrique Álvarez, Jesús Anero
Some aspects of quantum field theory in a general (i.e. non inertial) frame of Minkowski spacetime are studied. Conditions for the presence of horizons as well as for the modificat…
Witten diagrams in momentum space and one graviton exchange between scalars in Weyl invariant unimodular gravity
J. Anero, Carmelo P. Martin
We tackle head-on the computation of the -channel Witten diagram in momentum space corresponding to the exchange of a graviton between minimally coupled scalars in Weyl invarian…
Some consequences of the Kerr-Schild gauge
Enrique Álvarez, Jesús Anero
Generalized Kerr-Schild nilpotent deformations of an arbitrary background spacetime $\overline{g}_{\m\n}(x)$ are considered. Those are of the form $\overline{g}_{\m\n}+l_\m l_\n$ w…
Superposition of gravitational fields
Enrique Álvarez, Jesús Anero
Linear superposition of gravitational fields is shown to be possible for a large class of spacetimes, in some specific coordinates. Explicit examples are presented.
Gravitons in a gravitational plane wave
Enrique Alvarez, Jesus Anero, Irene Sanchez-Ruiz
Gravitational plane waves (when Ricci flat) belong to the VSI family. The achronym VSI stands for vanishing scalar invariants, meaning that all scalar invariants built out of Riema…
The origin of the cosmological constant
Enrique Álvarez, Jesús Anero, Irene Sánchez-Ruiz
It is well-known that in unimodular gravity the cosmological constant is not sourced by a constant energy density, but rather appears as some sort of integration constant. In this…
Quantum gravity in JNW spacetime
Enrique Alvarez, Jesus Anero
In this paper we study the behavior of a scalar field coupled to gravitons on the Janis-Newman-Winicour background, which somewhat interpolates between Minkowski and Schwarzschild…
The one-loop unimodular graviton propagator in any dimension
Jesus Anero, Carmelo P. Martin, Eduardo Velasco-Aja
For unimodular gravity, we work out, by using dimensional regularization, the complete one-loop correction to the graviton propagator in any space-time dimension. The computation i…
The quantum dynamics of Lagrange multipliers
Enrique Álvarez, Jesús Anero, Carmelo P. Martin +1
When implementing a non-linear constraint in quantum field theory by means of a Lagrange multiplier, , it is often the case that quantum dynamics induce quadratic and even hi…
Physical charges versus conformal invariance in unimodular gravity
Enrique Alvarez, Jesus Anero, Irene Sanchez-Ruiz
Unimodularity can be implemented in different ways. In this paper we consider only the formulation of Unimodular Gravity in which the unimodular metric is obtained out of an unrest…
Variations on the Goroff-Sagnotti operator
Enrique Álvarez, Jesus Anero, Eduardo Velasco-Aja
The effect of modifying General Relativity with the addition of some higher dimensional operators, generalizations of the Goroff-Sagnotti operator, is discussed. We determine in pa…
Unimodular gravity and the gauge/gravity duality
Jesus Anero, Carmelo P. Martin
Unimodular gravity can be formulated so that transverse diffeomorphisms and Weyl transformations are symmetries of the theory. For this formulation of unimodular gravity, we work o…
Quantum corrections to Einstein's equations
Eduardo Velasco-Aja, Jesus Anero
In this master thesis, the Frobenius power series method is used to find spherically symmetric and static vacuum solutions to quadratic and cubic gravitational actions, representin…
The fate of horizons under quantum corrections
Enrique Álvarez, Jesús Anero, Eduardo Velasco-Aja
We have studied a lagrangian in which the Einstein-Hilbert term is deformed by the Weyl cube operator, which is the lowest-dimension operator that is non-vanishing on shell and app…
Covariant techniques in Quantum Field Theory
Enrique Alvarez, Jesus Anero
In this paper some techniques useful to perform quantum field theory computations in a covariant manner are reviewed. In particular the background field gauge, the zeta function re…
Divergences of the scalar sector of quadratic gravity
Enrique Álvarez, Jesús Anero
The divergences coming from a particular sector of gravitational fluctuations around a generic background in general theories of quadratic gravity are analyzed. They can be summari…
Unimodular Cosmological models
Enrique Alvarez, Jesus Anero
It is claimed that in the unimodular gravity framework the observational fact of exponential expansion of the universe cannot be taken as evidence for the presence for a cosmologic…
Some comments on the Hamiltonian for Unimodular Gravity
Enrique Álvarez, Jesús Anero
Several alternative formulations of the first order approach to unimodular gravity are presented. There is always a particular one such that it is {\em classically} equivalent to t…
Effective action in elliptic and hyperbolic spacetimes
Enrique Alvarez, Jesus Anero
The full one-loop (scalar) effective action is computed for both hyperbolic and elliptic spacetimes.
Weighing the Vacuum Energy
Enrique Alvarez, Jesus Anero, Raquel Santos-Garcia
We discuss the weight of vacuum energy in various contexts. First, we compute the vacuum energy for flat spacetimes of the form , where $\mathbb{T}^…
Structural stability of spherical horizons
Enrique Alvarez, Jesus Anero, Raquel Santos-Garcia
This paper is concerned with the structural stability of spherical horizons. By this we mean stability with respect to variations of the second member of the corresponding differen…