Álvaro de la Cruz-Dombriz
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
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Álvaro de la Cruz-Dombriz has a total of 86 co-authors. Here are the top co-authors by number of shared publications:
- José Alberto Ruiz Cembranos
Departamento de Física Teórica, Universidad Complutense de Madrid, 28040 Madrid, Spain
24 shared publications - Antonio Dobado
Departamento de Física Teórica and Instituto IPARCOS Universidad Complutense 28040 Madrid Spain
23 shared publications - Antonio L. Maroto
Departamento de Física Teórica and Instituto de Física de Partículas y del Cosmos (IPARCOS-UCM), Universidad Complutense de Madrid, 28040 Madrid, Spain
20 shared publications - Peter K. S. Dunsby
Centre for Space Research North-West University 2520 Potchefstroom South Africa
11 shared publications - Diego Sáez-Chillón Gómez
University of Valladolid UVA
10 shared publications - Adrián Casado-Turrión
Departamento de Física Teórica and Instituto IPARCOS Universidad Complutense 28040 Madrid Spain
7 shared publications
Latest Publications
- 5 October 2026
- Published by American Physical Society (APS) in Physical Review D
- Vol. 114 (8) , 084011
Past and future isotropization in f ( R ) dark energy models
We present a dynamical system analysis for the homogeneous and anisotropic Bianchi I cosmology in the context of Hu-Sawicki $f(R)$ gravity with parameters ${n,{C}_{1}}={1,1}$. Deriving the corresponding four-dimensional dynamical system from the field equations allows us to find the fixed points of the system in both the vacuum and matter cases alongside their stability. This approach also provides analytical expressions for both the cosmic expansion and shear of each fixed point. More importantly, it allows us to address one of the least satisfying aspects of the $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ picture: the apparent fine-tuning of the initial state. We show that, for the chosen parameters, Hu-Sawicki gravity allows for isotropization both in the past and in the future for both vacuum and matter, demonstrating that Hu-Sawicki gravity may alleviate the anisotropy-related initial-condition problem for a subsequent inflationary phase. For the matter case, the analysis was subdivided into the dust and radiation cases, and we show that both cases exhibit past and future isotropization. The obtained results also revealed interesting aspects of the phase space such as the existence and phenomenology of lines and two-dimensional sheets of fixed points.- 5 October 2026
- Published by American Physical Society (APS) in Physical Review D
- Vol. 114 (8) , 084011
Past and future isotropization in f ( R ) dark energy models
We present a dynamical system analysis for the homogeneous and anisotropic Bianchi I cosmology in the context of Hu-Sawicki $f(R)$ gravity with parameters ${n,{C}_{1}}={1,1}$. Deriving the corresponding four-dimensional dynamical system from the field equations allows us to find the fixed points of the system in both the vacuum and matter cases alongside their stability. This approach also provides analytical expressions for both the cosmic expansion and shear of each fixed point. More importantly, it allows us to address one of the least satisfying aspects of the $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ picture: the apparent fine-tuning of the initial state. We show that, for the chosen parameters, Hu-Sawicki gravity allows for isotropization both in the past and in the future for both vacuum and matter, demonstrating that Hu-Sawicki gravity may alleviate the anisotropy-related initial-condition problem for a subsequent inflationary phase. For the matter case, the analysis was subdivided into the dust and radiation cases, and we show that both cases exhibit past and future isotropization. The obtained results also revealed interesting aspects of the phase space such as the existence and phenomenology of lines and two-dimensional sheets of fixed points.- Open Access
- 29 July 2026
- Published by Elsevier in Physics of the Dark Universe
- Vol. 53
On relativistic observables in black bounce spacetimes
- 29 July 2026
- Published by Elsevier in Physics of the Dark Universe
- Vol. 53
Open AccessOn relativistic observables in black bounce spacetimes
- Open Access
- 19 January 2026
- Published by Elsevier in Physics of the Dark Universe
- Vol. 51
Implications of f(R) gravity on late-time cosmic structure growth through a complete description of density perturbations
- 19 January 2026
- Published by Elsevier in Physics of the Dark Universe
- Vol. 51
Open AccessImplications of f(R) gravity on late-time cosmic structure growth through a complete description of density perturbations
- 12 November 2025
- Published by American Physical Society (APS) in Physical Review D
- Vol. 112 (10)
Dynamical dark energy in models with an evolution close to Λ CDM
- 12 November 2025
- Published by American Physical Society (APS) in Physical Review D
- Vol. 112 (10)
Dynamical dark energy in models with an evolution close to Λ CDM
- Open Access
Dynamical dark energy in models with evolution close to $Λ$CDM
In this communication we address whether or not there is an equivalence between the kinematical and dynamical descriptions of the spatially flat $Λ$CDM model. We address this by investigating whether an almost $Λ$CDM expansion history ($j(z)\approx1$) corresponds to an almost $Λ$CDM model ($w_{\rm DE}(z)\approx-1$) by considering two particular explicit examples. At least for the cases considered, this turns out not to be the case. Instead, what we find is that an almost $Λ$CDM cosmic evolution rather corresponds to an \emph{almost unified dark fluid model}. Considering that one never gets the exact condition $j(z)=1$ from any cosmographic data sets, this raises further questions on whether the $Λ$CDM model is the best candidate for the standard model of the evolution of the universe.Open AccessDynamical dark energy in models with evolution close to $Λ$CDM
In this communication we address whether or not there is an equivalence between the kinematical and dynamical descriptions of the spatially flat $Λ$CDM model. We address this by investigating whether an almost $Λ$CDM expansion history ($j(z)\approx1$) corresponds to an almost $Λ$CDM model ($w_{\rm DE}(z)\approx-1$) by considering two particular explicit examples. At least for the cases considered, this turns out not to be the case. Instead, what we find is that an almost $Λ$CDM cosmic evolution rather corresponds to an \emph{almost unified dark fluid model}. Considering that one never gets the exact condition $j(z)=1$ from any cosmographic data sets, this raises further questions on whether the $Λ$CDM model is the best candidate for the standard model of the evolution of the universe. - 28 October 2025
- Published by American Physical Society (APS) in Physical Review D
- Vol. 112 (8)
Close hyperbolic encounters in f ( R ) gravity
- 28 October 2025
- Published by American Physical Society (APS) in Physical Review D
- Vol. 112 (8)
Close hyperbolic encounters in f ( R ) gravity
- Open Access
- 28 August 2025
- Published by Springer Nature in The European Physical Journal C
- Vol. 85 (8) , 1-11
Vector wormholes as conduits for matter interaction
In this work, we focus on the dynamics of a massive one-form field, B, often referred to simply as a vector field, that is minimally coupled to standard Einstein gravity. In the framework of four-dimensional spacetimes, the theory of a massive one-form propagates three massive vector degrees of freedom. The inclusion of a self-interacting potential in this theory results in the breaking of gauge invariance. The breaking of such a fundamental symmetry in Classical Electromagnetism may introduce a ghost mode in massive vector theories, which generally leads to their instability. However, in the context of wormhole physics, the existence of at least one ghost degree of freedom turns out to be a necessary condition to support these exotic geometries within effective field theories. This requirement serves as a strong motivation for our work, wherein we explore the role and phenomenology of massive one-forms, minimally coupled to Einstein gravity, in providing the necessary conditions to sustain wormhole spacetimes. We further analyze the coupling of matter fields to such a vector field through conformal couplings and explore their impact on energy conditions and the physical viability of wormhole solutions.
- 28 August 2025
- Published by Springer Nature in The European Physical Journal C
- Vol. 85 (8) , 1-11
Open AccessVector wormholes as conduits for matter interaction
In this work, we focus on the dynamics of a massive one-form field, B, often referred to simply as a vector field, that is minimally coupled to standard Einstein gravity. In the framework of four-dimensional spacetimes, the theory of a massive one-form propagates three massive vector degrees of freedom. The inclusion of a self-interacting potential in this theory results in the breaking of gauge invariance. The breaking of such a fundamental symmetry in Classical Electromagnetism may introduce a ghost mode in massive vector theories, which generally leads to their instability. However, in the context of wormhole physics, the existence of at least one ghost degree of freedom turns out to be a necessary condition to support these exotic geometries within effective field theories. This requirement serves as a strong motivation for our work, wherein we explore the role and phenomenology of massive one-forms, minimally coupled to Einstein gravity, in providing the necessary conditions to sustain wormhole spacetimes. We further analyze the coupling of matter fields to such a vector field through conformal couplings and explore their impact on energy conditions and the physical viability of wormhole solutions.
- Open Access
- 7 July 2025
- Published by Springer Nature in The European Physical Journal C
- Vol. 85 (7) , 1-22
Constraining viscous-fluid models in f(Q) gravity with data
We investigate the impact of bulk viscosity on the accelerating expansion and large-scale structure formation of a Universe in which the underlying gravitational interaction is described by f(Q) gravity. Various paradigmatic choices of the f(Q) gravity theory, including power-law, exponential, and logarithmic models, are considered. To test the cosmological viability of these f(Q) gravity models, we use the Baryon Acoustic Oscillations (BAO) measurements from the Dark Energy Spectroscopic Instrument (DESI) Survey, cosmic chronometers (CC) from Hubble measurements, the SNIa distance moduli measurements from the PantheonP + SH0ES, growth rate (f-data), and redshift-space distortions $$(f\sigma _8)$$ datasets, the latter two once the linear cosmological perturbations, growth rate f(z), and redshift-space distortion $$f\sigma _8(z)$$ are studied. Thus, we perform the combined analyses for: PantheonP + SH0ES, PantheonP + SH0ES + f, and PantheonP + SH0ES + $$f\sigma _8$$ . We compute the best-fit values $$\varOmega _m,$$ $$H_0\,\mathrm {(km/s/Mpc)},$$ $$r_d,$$ $$M_{abs},$$ $$\gamma ,$$ $$\sigma _8,$$ n, p and $$\varGamma $$ including the bulk viscosity coefficient $$\zeta .$$ Through a detailed statistical analysis, based on the Akaike Information Criterion (AIC) and Bayesian/Schwartz Information Criterion (BIC), a statistical comparison of the f(Q) gravity models with $$\varLambda $$ CDM is made. Among the three f(Q) models, only the non-viscous f(Q) power-law model yields robust parameter estimates and substantial observational support without any outright rejections. In contrast, both exponential and logarithmic f(Q) models (with or without bulk viscosity) are rejected by multiple model selection criteria. Moreover, adding bulk viscosity consistently increases $$\varDelta $$ AIC and $$\varDelta $$ BIC values, indicating that its inclusion is not statistically justified.- 7 July 2025
- Published by Springer Nature in The European Physical Journal C
- Vol. 85 (7) , 1-22
Open AccessConstraining viscous-fluid models in f(Q) gravity with data
We investigate the impact of bulk viscosity on the accelerating expansion and large-scale structure formation of a Universe in which the underlying gravitational interaction is described by f(Q) gravity. Various paradigmatic choices of the f(Q) gravity theory, including power-law, exponential, and logarithmic models, are considered. To test the cosmological viability of these f(Q) gravity models, we use the Baryon Acoustic Oscillations (BAO) measurements from the Dark Energy Spectroscopic Instrument (DESI) Survey, cosmic chronometers (CC) from Hubble measurements, the SNIa distance moduli measurements from the PantheonP + SH0ES, growth rate (f-data), and redshift-space distortions $$(f\sigma _8)$$ datasets, the latter two once the linear cosmological perturbations, growth rate f(z), and redshift-space distortion $$f\sigma _8(z)$$ are studied. Thus, we perform the combined analyses for: PantheonP + SH0ES, PantheonP + SH0ES + f, and PantheonP + SH0ES + $$f\sigma _8$$ . We compute the best-fit values $$\varOmega _m,$$ $$H_0\,\mathrm {(km/s/Mpc)},$$ $$r_d,$$ $$M_{abs},$$ $$\gamma ,$$ $$\sigma _8,$$ n, p and $$\varGamma $$ including the bulk viscosity coefficient $$\zeta .$$ Through a detailed statistical analysis, based on the Akaike Information Criterion (AIC) and Bayesian/Schwartz Information Criterion (BIC), a statistical comparison of the f(Q) gravity models with $$\varLambda $$ CDM is made. Among the three f(Q) models, only the non-viscous f(Q) power-law model yields robust parameter estimates and substantial observational support without any outright rejections. In contrast, both exponential and logarithmic f(Q) models (with or without bulk viscosity) are rejected by multiple model selection criteria. Moreover, adding bulk viscosity consistently increases $$\varDelta $$ AIC and $$\varDelta $$ BIC values, indicating that its inclusion is not statistically justified. - 31 March 2025
- Published by American Physical Society (APS) in Physical Review D
- Vol. 111 (6)
Toward a realistic Buchdahl limit in theories of gravity- 31 March 2025
- Published by American Physical Society (APS) in Physical Review D
- Vol. 111 (6)
Toward a realistic Buchdahl limit in theories of gravity- Open Access
- 21 February 2025
- Published by IOP Publishing in Classical and Quantum Gravity
- Vol. 42 (6) , 065001
Smearing out contact terms in ghost-free infinite derivative quantum gravity
In the context of ghost-free infinite derivative gravity, we consider the single graviton exchange between two spinless particles, a spinless particle and a photon, or between a spinless particle and a spin-1/2 particle. To this end, we compute the gravitational potential for the three aforementioned cases and derive the O ( G ℏ 2 ) correction that arises at the linearised level. In the local theory, it is well-known that such a correction appears in the form of a Dirac delta function. Here, we show that this correction is smeared out for the nonlocal theory and, in contrast to the local theory, takes on non-zero values for a non-zero separation between the two particles. In the case of the single graviton exchange between a spinless particle and a spin-1/2 particle, we also compute the O ( G ℏ ) correction that arises in the non-static case within the non-relativistic approximation and show that it is finite in the nonlocal theory.
- 21 February 2025
- Published by IOP Publishing in Classical and Quantum Gravity
- Vol. 42 (6) , 065001
Open AccessSmearing out contact terms in ghost-free infinite derivative quantum gravity
In the context of ghost-free infinite derivative gravity, we consider the single graviton exchange between two spinless particles, a spinless particle and a photon, or between a spinless particle and a spin-1/2 particle. To this end, we compute the gravitational potential for the three aforementioned cases and derive the O ( G ℏ 2 ) correction that arises at the linearised level. In the local theory, it is well-known that such a correction appears in the form of a Dirac delta function. Here, we show that this correction is smeared out for the nonlocal theory and, in contrast to the local theory, takes on non-zero values for a non-zero separation between the two particles. In the case of the single graviton exchange between a spinless particle and a spin-1/2 particle, we also compute the O ( G ℏ ) correction that arises in the non-static case within the non-relativistic approximation and show that it is finite in the nonlocal theory.