Jesus Anero - Academia.edu (original) (raw)

Papers by Jesus Anero

International Journal of Modern Physics A

There is a formulation of unimodular gravity (UG) in which the unimodular metric is obtained out ... more There is a formulation of unimodular gravity (UG) in which the unimodular metric is obtained out of an unrestricted one as [Formula: see text]. This unrestricted metric is only defined up to a Weyl rescaling. Physical charges like ADM energy or horizon entropy, however, are not Weyl invariant in general. In this paper a Weyl invariant definition of some physical charges is given.

Physical Review D

Unimodular gravity can be formulated so that transverse diffeomorphisms and Weyl transformations ... more 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 out the two-point and threepoint h μν contributions to the on shell classical gravity action in the leading approximation and for an Euclidean anti de Sitter background. We conclude that these contributions do not agree with those obtained by using general relativity due to IR divergent contact terms. The subtraction of these IR divergent terms yields the same IR finite result for both unimodular gravity and general relativity. Equivalence between unimodular gravity and general relativity with regard to the gauge/gravity duality thus emerges in a nontrivial way.

arXiv (Cornell University), Jul 8, 2019

The generalization of scale invariance when gravitational effects are considered is Weyl invarian... more The generalization of scale invariance when gravitational effects are considered is Weyl invariance, namely, invariance under (global or local) rescalings of the metric. In this work, we discuss in some details the implications of the fact that the value of the anomaly for the global Weyl invariant coupling of scalar fields to gravity is sensitive to the dynamics (or absence thereof) of the gravitational field.

SpringerBriefs in Physics

arXiv (Cornell University), Sep 16, 2021

It is claimed that in the unimodular gravity framework the observational fact of exponential expa... more 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 cosmological constant or similar quintessence.

Classical and Quantum Gravity

The divergences coming from a particular sector of gravitational fluctuations around a generic ba... more 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 summarized in a particular type of scalar model, whose properties are discussed. We analyze in particular with some care arguments against this particular scalar model being unitary. We also discussed the product anomaly in this context.

One-loop counterterms are computed in the first order formalism for the EinsteinHilbert action wi... more One-loop counterterms are computed in the first order formalism for the EinsteinHilbert action with a minimally coupled scalar field using the background field method and the heat kernel technique. The off-shell divergent piece in the harmonic gauge is exactly the same as the one first found by ’t Hooft and Veltman.

arXiv: High Energy Physics - Theory, 2020

The structural stability of Schwarzschild-de Sitter's horizon is studied. It is claimed that ... more The structural stability of Schwarzschild-de Sitter's horizon is studied. It is claimed that when lagrangians incorporating terms quadratic in curvature are taken seriously, the generic solution in the asymptotic regime (large radius) can be matched not only with the usual solutions with horizons (like Schwarzschild-de Sitter) but also with a more generic (in the sense that it depends on more arbitrary parameters) horizonless family of solutions.

Exponential expansion in Unimodular Gravity is possible even in the absence of a constant potenti... more Exponential expansion in Unimodular Gravity is possible even in the absence of a constant potential; id est for free fields. This is at variance with the case in General Relativity. ar X iv :2 10 9. 08 07 7v 1 [ gr -q c] 1 6 Se p 20 21

arXiv: High Energy Physics - Theory, 2017

One-loop counterterms are computed in first order formalism for the Einstein-Hilbert action using... more One-loop counterterms are computed in first order formalism for the Einstein-Hilbert action using the background field method and the heat kernel technique. The obtained result coincides with the result found by Hooft and Veltman in second order formalism.

arXiv: High Energy Physics - Theory, 2018

A definition of quasi-local energy in a gravitational field based upon its embedding into flat sp... more A definition of quasi-local energy in a gravitational field based upon its embedding into flat space is discussed. The outcome is not satisfactory from many points of view.

arXiv: High Energy Physics - Theory, 2019

The presence of gravity generalizes the notion of scale invariance to Weyl invariance, namely, in... more The presence of gravity generalizes the notion of scale invariance to Weyl invariance, namely, invariance under local rescalings of the metric. In this work, we have computed the Weyl anomaly for various classically scale or Weyl invariant theories, making particular emphasis on the differences that arise when gravity is taken as a dynamical fluctuation instead of as a non-dynamical background field. We find that the value of the anomaly for the Weyl invariant coupling of scalar fields to gravity is sensitive to the dynamical character of the gravitational field, even when computed in constant curvature backgrounds. We also discuss to what extent those effects are potentially observable.

Physical Review D, 2021

Several alternative formulations of the first order approach to unimodular gravity are presented.... more Several alternative formulations of the first order approach to unimodular gravity are presented. There is always a particular one such that it is classically equivalent to the second order formulation; this we call educated. It is often at variance with the naive approach, in which the lagrangian is taken as given exactly by the same expression as in the second order formulation; only the number and character of the independent variables changes. Namely, typically some of the momenta are now considered as coordinates. The ensuing Hamiltonians are thereby discussed and their physical differences pointed out. ar X iv :2 10 7. 08 89 3v 1 [ gr -q c] 1 9 Ju l 2 02 1

Particle Physics at the Silver Jubilee of Lomonosov Conferences, 2019

We consider the most general action for gravity which is quadratic in curvature. In this case fir... more We consider the most general action for gravity which is quadratic in curvature. In this case first order and second order formalisms are not equivalent. This framework is a good candidate for a unitary and renormalizable theory of the gravitational field; in particular, there are no propagators falling down faster than 1 p 2. The UV regime is in a conformal invariant phase; only when Weyl invariance is broken through the coupling to matter can an Einstein-Hilbert term (and its corresponding Planck mass scale) be generated.

Physical Review D, 2021

Several alternative formulations of the first order approach to unimodular gravity are presented.... more Several alternative formulations of the first order approach to unimodular gravity are presented. There is always a particular one such that it is classically equivalent to the second order formulation; this we call educated. It is often at variance with the naive approach, in which the lagrangian is taken as given exactly by the same expression as in the second order formulation; only the number and character of the independent variables changes. Namely, typically some of the momenta are now considered as coordinates. The ensuing Hamiltonians are thereby discussed and their physical differences pointed out.

Classical and Quantum Gravity, 2021

This paper is concerned with the structural stability of spherical horizons. By this we mean stab... more 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 differential equations, corresponding to the inclusion of the contribution of operators quadratic in curvature. This we do both in the usual second order approach (in which the independent variable is the spacetime metric) and in the first order one (where the independent variables are the spacetime metric and the connection field). In second order, it is claimed that the generic solution in the asymptotic regime (large radius) can be matched not only with the usual solutions with horizons (like Schwarzschild-de Sitter) but also with a more generic (in the sense that it depends on more arbitrary parameters) horizonless family of solutions. It is however remarkable that these horizonless solutions are absent in the restricted (that is, when the background connection is the metric one) first order approach.

Classical and Quantum Gravity, 2021

Classical and Quantum Gravity, 2020

A ghost free massive deformation of unimodular gravity (UG), in the spirit of mimetic massive gra... more A ghost free massive deformation of unimodular gravity (UG), in the spirit of mimetic massive gravity, is shown to exist. This construction avoids the no-go theorem for a Fierz-Pauli type of mass term in UG by giving up on Lorentz invariance. In our framework, the mimetic degree of freedom vanishes on-shell.

International Journal of Modern Physics A

There is a formulation of unimodular gravity (UG) in which the unimodular metric is obtained out ... more There is a formulation of unimodular gravity (UG) in which the unimodular metric is obtained out of an unrestricted one as [Formula: see text]. This unrestricted metric is only defined up to a Weyl rescaling. Physical charges like ADM energy or horizon entropy, however, are not Weyl invariant in general. In this paper a Weyl invariant definition of some physical charges is given.

Physical Review D

Unimodular gravity can be formulated so that transverse diffeomorphisms and Weyl transformations ... more 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 out the two-point and threepoint h μν contributions to the on shell classical gravity action in the leading approximation and for an Euclidean anti de Sitter background. We conclude that these contributions do not agree with those obtained by using general relativity due to IR divergent contact terms. The subtraction of these IR divergent terms yields the same IR finite result for both unimodular gravity and general relativity. Equivalence between unimodular gravity and general relativity with regard to the gauge/gravity duality thus emerges in a nontrivial way.

arXiv (Cornell University), Jul 8, 2019

The generalization of scale invariance when gravitational effects are considered is Weyl invarian... more The generalization of scale invariance when gravitational effects are considered is Weyl invariance, namely, invariance under (global or local) rescalings of the metric. In this work, we discuss in some details the implications of the fact that the value of the anomaly for the global Weyl invariant coupling of scalar fields to gravity is sensitive to the dynamics (or absence thereof) of the gravitational field.

SpringerBriefs in Physics

arXiv (Cornell University), Sep 16, 2021

It is claimed that in the unimodular gravity framework the observational fact of exponential expa... more 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 cosmological constant or similar quintessence.

Classical and Quantum Gravity

The divergences coming from a particular sector of gravitational fluctuations around a generic ba... more 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 summarized in a particular type of scalar model, whose properties are discussed. We analyze in particular with some care arguments against this particular scalar model being unitary. We also discussed the product anomaly in this context.

One-loop counterterms are computed in the first order formalism for the EinsteinHilbert action wi... more One-loop counterterms are computed in the first order formalism for the EinsteinHilbert action with a minimally coupled scalar field using the background field method and the heat kernel technique. The off-shell divergent piece in the harmonic gauge is exactly the same as the one first found by ’t Hooft and Veltman.

arXiv: High Energy Physics - Theory, 2020

The structural stability of Schwarzschild-de Sitter's horizon is studied. It is claimed that ... more The structural stability of Schwarzschild-de Sitter's horizon is studied. It is claimed that when lagrangians incorporating terms quadratic in curvature are taken seriously, the generic solution in the asymptotic regime (large radius) can be matched not only with the usual solutions with horizons (like Schwarzschild-de Sitter) but also with a more generic (in the sense that it depends on more arbitrary parameters) horizonless family of solutions.

Exponential expansion in Unimodular Gravity is possible even in the absence of a constant potenti... more Exponential expansion in Unimodular Gravity is possible even in the absence of a constant potential; id est for free fields. This is at variance with the case in General Relativity. ar X iv :2 10 9. 08 07 7v 1 [ gr -q c] 1 6 Se p 20 21

arXiv: High Energy Physics - Theory, 2017

One-loop counterterms are computed in first order formalism for the Einstein-Hilbert action using... more One-loop counterterms are computed in first order formalism for the Einstein-Hilbert action using the background field method and the heat kernel technique. The obtained result coincides with the result found by Hooft and Veltman in second order formalism.

arXiv: High Energy Physics - Theory, 2018

A definition of quasi-local energy in a gravitational field based upon its embedding into flat sp... more A definition of quasi-local energy in a gravitational field based upon its embedding into flat space is discussed. The outcome is not satisfactory from many points of view.

arXiv: High Energy Physics - Theory, 2019

The presence of gravity generalizes the notion of scale invariance to Weyl invariance, namely, in... more The presence of gravity generalizes the notion of scale invariance to Weyl invariance, namely, invariance under local rescalings of the metric. In this work, we have computed the Weyl anomaly for various classically scale or Weyl invariant theories, making particular emphasis on the differences that arise when gravity is taken as a dynamical fluctuation instead of as a non-dynamical background field. We find that the value of the anomaly for the Weyl invariant coupling of scalar fields to gravity is sensitive to the dynamical character of the gravitational field, even when computed in constant curvature backgrounds. We also discuss to what extent those effects are potentially observable.

Physical Review D, 2021

Several alternative formulations of the first order approach to unimodular gravity are presented.... more Several alternative formulations of the first order approach to unimodular gravity are presented. There is always a particular one such that it is classically equivalent to the second order formulation; this we call educated. It is often at variance with the naive approach, in which the lagrangian is taken as given exactly by the same expression as in the second order formulation; only the number and character of the independent variables changes. Namely, typically some of the momenta are now considered as coordinates. The ensuing Hamiltonians are thereby discussed and their physical differences pointed out. ar X iv :2 10 7. 08 89 3v 1 [ gr -q c] 1 9 Ju l 2 02 1

Particle Physics at the Silver Jubilee of Lomonosov Conferences, 2019

We consider the most general action for gravity which is quadratic in curvature. In this case fir... more We consider the most general action for gravity which is quadratic in curvature. In this case first order and second order formalisms are not equivalent. This framework is a good candidate for a unitary and renormalizable theory of the gravitational field; in particular, there are no propagators falling down faster than 1 p 2. The UV regime is in a conformal invariant phase; only when Weyl invariance is broken through the coupling to matter can an Einstein-Hilbert term (and its corresponding Planck mass scale) be generated.

Physical Review D, 2021

Several alternative formulations of the first order approach to unimodular gravity are presented.... more Several alternative formulations of the first order approach to unimodular gravity are presented. There is always a particular one such that it is classically equivalent to the second order formulation; this we call educated. It is often at variance with the naive approach, in which the lagrangian is taken as given exactly by the same expression as in the second order formulation; only the number and character of the independent variables changes. Namely, typically some of the momenta are now considered as coordinates. The ensuing Hamiltonians are thereby discussed and their physical differences pointed out.

Classical and Quantum Gravity, 2021

This paper is concerned with the structural stability of spherical horizons. By this we mean stab... more 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 differential equations, corresponding to the inclusion of the contribution of operators quadratic in curvature. This we do both in the usual second order approach (in which the independent variable is the spacetime metric) and in the first order one (where the independent variables are the spacetime metric and the connection field). In second order, it is claimed that the generic solution in the asymptotic regime (large radius) can be matched not only with the usual solutions with horizons (like Schwarzschild-de Sitter) but also with a more generic (in the sense that it depends on more arbitrary parameters) horizonless family of solutions. It is however remarkable that these horizonless solutions are absent in the restricted (that is, when the background connection is the metric one) first order approach.

Classical and Quantum Gravity, 2021

Classical and Quantum Gravity, 2020

A ghost free massive deformation of unimodular gravity (UG), in the spirit of mimetic massive gra... more A ghost free massive deformation of unimodular gravity (UG), in the spirit of mimetic massive gravity, is shown to exist. This construction avoids the no-go theorem for a Fierz-Pauli type of mass term in UG by giving up on Lorentz invariance. In our framework, the mimetic degree of freedom vanishes on-shell.