arXiv subjects

Alex E. Bernardini

Publications and source records attributed to Alex E. Bernardini.

At least 19 recordsLinked to original sources

arXiv2026

Hubble tension problem encompassed by phase-space quantum cosmology

Analytical solutions encompassing the so-called Hubble tension problem are revisited through the framework of Weyl--Wigner quantum mechanics and discussed in the context of generalized phase-space scenarios of quantum cosmology. After reviewing the nature of the problem and its recent developments, an extended formulation constructed within the quantum phase-space framework to address the Hubble tension is proposed. For the quantum cosmology described in the minisuperspace framework through (generic) localized phase-space quantum states, when residual quantum corrections to the Einstein--Friedmann equation are analytically derived, quantum effects are shown to suppress the Hubble tension divergence between early- and late-time predictions. Besides addressing the Hubble tension problem within the standard $Λ$CDM cosmological model, our approach encompasses generalized quantum cosmological scenarios that also include curvature and dark sector modifications.

gr-qc↗

arXiv2026

On dark sector scalar field theories driven by cosmological $c$-fields

The interplay of Hoyle-Narlikar (HN) creation field cosmology and scalar field models for the dark sector, including the generalized Chaplygin Gas (GCG), is investigated . Though originating from distinct theoretical frameworks, both the inclusion and the non-inclusion of the creation field degree of freedom (DoF) involve a scalar DoF, which addresses some of the limitations of the standard $Λ$CDM model. Using a Lagrangian scalar field formulation and the first-order Hamiltonian reconstruction method, the HN $c$-field dynamics is shown to be encompassed by the GCG equation of state through an equivalent modified scalar field theory. Late-time acceleration and stability of linear perturbations are derived within this unified description. Our results suggest that creation field cosmologies may be embedded in a broader class of scalar field models which encompasses subtle modifications to the Hubble expansion rate and related physical observables.

gr-qc↗

arXiv2026

Toda-like Hamiltonian as a probe for quantized prey-predator dynamics

Phase-space features of a reduced version of the Toda-like Hamiltonian, $\mathcal{H}(x,\,k)$, written in a form constrained by the condition $\partial^2 \mathcal{H} / \partial x \partial k = 0$, with $x$ and $k$ as canonically conjugate variables, are analyzed in terms of Wigner currents. For Wigner currents convoluted with either thermodynamic or Gaussian ensembles, the underlying Hamiltonian dynamics admits analytic corrections due to quantum distortions over the classical phase-space pattern, computed and interpreted through quantifiers of quantumness and stationarity. Notably, while emulating the Lotka-Volterra (LV) dynamics that describe ecological competition systems, the Toda-like classical dynamics allows for analytical solutions with computable periods corresponding to closed phase-space orbits of isotropic prey-predator population distributions. The essential conditions for understanding how classical and quantum evolution can coexist are provided at different scales of quantumness, driven by the associated convoluting ensemble parameter. In the case of Gaussian statistical ensembles, the exact profile of the quantum distortions over classical prey-predator phase-space trajectories is obtained non-perturbatively. Our results indicate that, besides the classical stability admitted by LV models, the Toda-like patterns also exhibit quantum stability. Therefore, this can be regarded as the first step as a predictive theoretical framework towards more robust descriptions of quantum patterns in competitive microscopic biosystems.

quant-ph↗

arXiv2025

Geometrical structure of the Wigner flow information quantifiers and hyperbolic stability in the phase-space framework

Quantifiers of stationarity, classicality, purity and vorticity are derived from phase-space differential geometrical structures within the Weyl-Wigner framework, after which they are related to the hyperbolic stability of classical and quantum-modified Hamiltonian (non-linear) equations of motion. By examining the equilibrium regime produced by such an autonomous system of ordinary differential equations, a correspondence between Wigner flow properties and hyperbolic stability boundaries in the phase-space is identified. Explicit analytical expressions for equilibrium-stability parameters are obtained for quantum Gaussian ensembles, wherein information quantifiers driven by Wigner currents are identified. Illustrated by an application to a Harper-like system, the results provide a self-contained analysis for identifying the influence of quantum fluctuations associated to the emergence of phase-space vorticity in order to quantify equilibrium and stability properties of Hamiltonian non-linear dynamics.

quant-ph↗

arXiv2025

Soft quantum back reaction to the Hubble tension: a smeared-out early time cosmological energy density

A theoretical explanation for the so-called Hubble tension is provided within the framework of phase-space quantum mechanics extended to (quantum) cosmology. Following a description of the overall nature of this tension, with due attention to recent observational developments, a quantum cosmology framework based on the Weyl-Wigner phase-space quantum approach is presented. This circumvents the discrepancy between early- and late-time Universe predictions for the Hubble constant, $H_0$. The emergence of quantum-origin corrections dependent on a single parameter -- mediated by (generic) localized phase-space quantum states free of data analysis -- yields predictions for $H_0$ that smoothly interpolate between early- and late-time phenomenological values, thereby joining the plethora of solutions for the Hubble tension.

physics.gen-ph↗

arXiv2025

Phase-space gaussian ensemble quantum camouflage

Extending the phase-space description of the Weyl-Wigner quantum mechanics to a subset of non-linear Hamiltonians in position and momentum, gaussian functions are identified as the quantum ground state. Once a Hamiltonian, $H^{W}(q,\,p)$, is constrained by the $\partial ^2 H^{W} / \partial q \partial p = 0$ condition, flow properties for generic $1$-dim systems can be analytically obtained in terms of Wigner functions and Wigner currents. For gaussian statistical ensembles, the exact phase-space profile of the quantum fluctuations over the classical trajectories are found, so to interpret them as a suitable Hilbert space state configuration for confronting quantum and classical regimes. In particular, a sort of {\em quantum camouflage} where the stationarity of classical statistical ensembles can be camouflaged by the stationarity of gaussian quantum ensembles is identified. Besides the broadness of the framework worked out in some previous examples, our results provide an encompassing picture of quantum effects on non-linear dynamical systems which can be interpreted as a first step for finding the complete spectrum of non-standard Hamiltonians.

quant-ph↗

arXiv2025

Phase-space quantum distorted stability pattern for Aubry-André-Harper dynamics

Instability features associated to topological quantum domains which emerge from the Weyl-Wigner (WW) quantum phase-space description of Gaussian ensembles driven by Aubry-André-Harper (AAH) Hamiltonians are investigated. Hyperbolic equilibrium and stability patterns are then identified and classified according to the associated (nonlinear) AAH Hamiltonian parameters. Besides providing the tools for quantifying the information content of AAH systems, the Wigner flow patterns here discussed suggest a systematic procedure for identifying the role of quantum fluctuations over equilibrium and stability, in a framework which can be straightforwardly extended to describe the evolution of similar/modified AAH systems.

quant-ph↗

arXiv2025

Chaotic Behaviour of the Earth System in the Anthropocene

It is shown that the Earth System (ES) can, due to the impact of human activities, exhibit chaotic behaviour. Our arguments are based on the assumption that the ES can be described by a Landau-Ginzburg model, which, in itself, predicts that the ES evolves through regular trajectories in phase space towards a Hothouse Earth scenario under a finite amount of human-driven impact. Furthermore, we find that the equilibrium point for temperature fluctuations can exhibit bifurcations and a chaotic pattern if human impact follows a logistic map. Our final analysis includes interactions between different terms of the planetary boundaries in order to gauge the predictability of our model.

astro-ph.EP↗

arXiv2025

Algebraic solutions for $SU(2)\otimes SU(2)$ Hamiltonian eigensystems: generic statistical ensembles and a mesoscopic system application

Solutions of generic $SU(2)\otimes SU(2)$ Hamiltonian eigensystems are obtained through systematic manipulations of quartic polynomial equations. An {\em ansatz} for constructing separable and entangled eigenstate basis, depending on the quartic equation coefficients, is proposed. Besides the quantum concurrence for pure entangled states, the associated thermodynamic statistical ensembles, their partition function, quantum purity and quantum concurrence are shown to be straightforwardly obtained. Results are specialized to a $SU(2)\otimes SU(2)$ structure emulated by lattice-layer degrees of freedom of the Bernal stacked graphene, in a context that can be extended to several mesoscopic scale systems for which the onset from $SU(2)\otimes SU(2)$ Hamiltonians has been assumed.

quant-ph↗

arXiv2024

Extended Weyl-Wigner phase-space framework for non-linear systems: typical and modified prey-predator-like dynamics

The extension of the phase-space Weyl-Wigner quantum mechanics to the subset of Hamiltonians in the form of $H(q,\,p) = {K}(p) + {V}(q)$ (with $K(p)$ replacing single $p^2$ contributions) is revisited. Deviations from classical and stationary profiles are identified in terms of Wigner functions and Wigner currents for Gaussian and gamma/Laplacian distribution ensembles. The procedure is successful in accounting for the exact pattern of quantum fluctuations when compared with the classical phase-space pattern. General results are then specialized to some specific Hamiltonians revealing non-linear dynamics, and suggest a novel algorithm to treat quantum modifications mapped by Wigner currents. Our analysis shows that the framework encompasses, for instance, the quantized prey-predator-like scenarios subjected to statistical constraints.

quant-ph↗

arXiv2023

Asymmetrical braneworlds and the charged lepton mass spectrum

A braneworld mechanism for explaining the mass spectrum of the charged leptons is proposed. Based on the existence of an asymmetric warp factor for a $5+1$-dim braneworld scenario, the proper fractions between the masses of the electron, muon and tauon are achieved. As a straightforward consequence, our results coincide with the Koide's mass formula.

hep-th↗

arXiv2023

Quantum prey-predator dynamics: a gaussian ensemble analysis

Quantum frameworks for modeling competitive ecological systems and self-organizing structures have been investigated under multiple perspectives yielded by quantum mechanics. These comprise the description of the phase-space prey-predator competition dynamics in the framework of the Weyl-Wigner quantum mechanics. In this case, from the classical dynamics described by the Lotka-Volterra (LV) Hamiltonian, quantum states convoluted by statistical gaussian ensembles can be analytically evaluated. Quantum modifications on the patterns of equilibrium and stability of the prey-predator dynamics can then be identified. These include quantum distortions over the equilibrium point drivers of the LV dynamics which are quantified through the Wigner current fluxes obtained from an onset Hamiltonian background. In addition, for gaussian ensembles highly localized around the equilibrium point, stability properties are shown to be affected by emergent topological quantum domains which, in some cases, could lead either to extinction and revival scenarios or to the perpetual coexistence of both prey and predator agents identified as quantum observables in microscopic systems. Conclusively, quantum and gaussian statistical driving parameters are shown to affect the stability criteria and the time evolution pattern for such microbiological-like communities.

quant-ph↗

arXiv2023

Distorted stability pattern and chaotic features for quantized prey-predator-like dynamics

Non-equilibrium and instability features of prey-predator-like systems associated to topological quantum domains emerging from a quantum phase-space description are investigated in the framework of the Weyl-Wigner quantum mechanics. Reporting about the generalized Wigner flow for one-dimensional Hamiltonian systems, $\mathcal{H}(x,\,k)$, constrained by $\partial^2 \mathcal{H} / \partial x \, \partial k = 0$, the prey-predator dynamics driven by Lotka-Volterra (LV) equations is mapped onto the Heisenberg-Weyl non-commutative algebra, $[x,\,k] = i$, where the canonical variables $x$ and $k$ are related to the two-dimensional LV parameters, $y = e^{-x}$ and $z = e^{-k}$. From the non-Liouvillian pattern driven by the associated Wigner currents, hyperbolic equilibrium and stability parameters for the prey-predator-like dynamics are then shown to be affected by quantum distortions over the classical background, in correspondence with non-stationarity and non-Liouvillianity properties quantified in terms of Wigner currents and Gaussian ensemble parameters. As an extension, considering the hypothesis of discretizing the time parameter, non-hyperbolic bifurcation regimes are identified and quantified in terms of $z-y$ anisotropy and Gaussian parameters. The bifurcation diagrams exhibit, for quantum regimes, chaotic patterns highly dependent on Gaussian localization. Besides exemplifying a broad range of applications of the generalized Wigner information flow framework, our results extend, from the continuous (hyperbolic regime) to discrete (chaotic regime) domains, the procedure for quantifying the influence of quantum fluctuations over equilibrium and stability scenarios of LV driven systems.

quant-ph↗

arXiv2022

Non-commutative phase-space Lotka-Volterra dynamics: the quantum analogue

The Lotka-Volterra (LV) dynamics is investigated in the framework of the Weyl-Wigner (WW) quantum mechanics (QM) extended to one-dimensional Hamiltonian systems, $\mathcal{H}(x,\,k)$, constrained by the $\partial^2 \mathcal{H} / \partial x \, \partial k = 0$ condition. Supported by the Heisenberg-Weyl non-commutative algebra, where $[x,\,k] = i$, the canonical variables $x$ and $k$ are interpreted in terms of the LV variables, $y = e^{-x}$ and $z = e^{-k}$, eventually associated with the number of individuals in a closed competitive dynamics: the so-called prey-predator system. The WW framework provides the ground for identifying how classical and quantum evolution coexist at different scales, and for quantifying {\it quantum analogue} effects. Through the results from the associated Wigner currents, (non-)Liouvillian and stationary properties are described for thermodynamic and gaussian quantum ensembles in order to account for the corrections due to quantum features over the classical phase-space pattern yielded by the Hamiltonian description of the LV dynamics. In particular, for gaussian statistical ensembles, the Wigner flow framework provides the exact profile for the quantum modifications over the classical LV phase-space trajectories so that gaussian quantum ensembles can be interpreted as an adequate Hilbert space state configuration for comparing quantum and classical regimes. The generality of the framework developed here extends the boundaries of the understanding of quantum-like effects on competitive microscopical bio-systems.

quant-ph↗

arXiv2022

Gravity Localization on Intersecting Thick Braneworlds

The localization of gravity for (5 + 1)-dimensional intersecting thick braneworld models is thoroughly investigated. Departing from preliminary results for five independent proposals, from I to V, gravity is shown to be localized in the brane. In particular, for models from I to III, only the zero modes are analytically determined. On the other hand, for models IV and V, massive modes are all obtained: a finite number of massive states is identified for model IV, while an infinite but discrete number of massive states bounded from below is exhibited by model V. Considering that the discreteness of the graviton modes implies that gravity does not propagate in the co-dimensions, the naked singularities of models IV and V, at edges of space, are made harmless. To conclude, the phenomenological implications for sphere models, constructed out of models III and IV, are also discussed. According to such an overall classification, if the internal space is a sphere, model IV is shown to exhibit normalizable modes. More relevantly, for the sphere model assembled out of model III, the subtle property of reproducing a consistent Newtonian limit is identified.

hep-th↗

arXiv2022

Emergent time crystals from phase-space noncommutative quantum mechanics

It has been argued that the existence of time crystals requires a spontaneous breakdown of the continuous time translation symmetry so to account for the unexpected non-stationary behavior of quantum observables in the ground state. Our point is that such effects do emerge from position ($\hat{q}_i$) and/or momentum ($\hat{p}_i$) noncommutativity, i.e., from $[\hat{q}_i,\,\hat{q}_j]\neq 0$ and/or $[\hat{p}_i,\,\hat{p}_j]\neq 0$ (for $i\neq j$). In such a context, a predictive analysis is carried out for the $2$-dim noncommutative quantum harmonic oscillator through a procedure supported by the Weyl-Wigner-Groenewold-Moyal framework. This allows for the understanding of how the phase-space noncommutativity drives the amplitude of periodic oscillations identified as time crystals. A natural extension of our analysis also shows how the spontaneous formation of time quasi-crystals can arise.

quant-ph↗

arXiv2022

Generalized phase-space description of non-linear Hamiltonian systems and the Harper-like dynamics

Phase-space features of the Wigner flow for generic one-dimensional systems with a Hamiltonian, $H^{W}(q,\,p)$, constrained by the $\partial ^2 H^{W} / \partial q \partial p = 0$ condition are analytically obtained in terms of Wigner functions and Wigner currents. Liouvillian and stationary profiles are identified for thermodynamic (TD) and Gaussian quantum ensembles to account for exact corrections due to quantum modifications over a classical phase-space pattern. General results are then specialized to the Harper Hamiltonian system which, besides working as a feasible test platform for the framework here introduced, admits a statistical description in terms of TD and Gaussian ensembles, where the Wigner flow properties are all obtained through analytical tools. Quantum fluctuations over the classical regime are therefore quantified through probability and information fluxes whenever the classical Hamiltonian background is provided. Besides allowing for a broad range of theoretical applications, our results suggest that such a generalized Wigner approach works as a probe for quantumness and classicality of Harper-like systems, in a framework which can be extended to any quantum system described by Hamiltonians in the form of $H^{W}(q,\,p) = K(p) + V(q)$.

quant-ph↗

arXiv2022

(5+1)-Dimensional Analytical Brane-World Models: Intersecting Thick Branes

Two co-dimensional thick brane-worlds are investigated in quite general terms for two intersecting scalar fields generating the extra dimension defect. In general, when one considers two co-dimensional thick brane-worlds, the warp factor is constructed as a string-like defect. Considering a twofold-warp factor constructed from two intersecting warp factors, an alternative bulk configuration is examined. With the brane localization thus driven by two crossing scalar fields, the possible solvable models obtained from such a two co-dimensional setup are systematically discussed. The obtained solutions are classified as five different models organized into two subsets for which some of their physical properties are evaluated. For models $I$ and $II$, in the first subset, Einstein equation solutions are rigidly defined, up to some arbitrary constant. For models $III$, $IV$ and $V$, in the second subset, an additional degree of freedom not constrained by Einstein equations is admitted. The solutions are all obtained from a departure statement of assuming a conformally flat metric for the internal space, which is concomitant to the proper choice of coordinates. Eventual singularities in the curvature are identified, however, without affecting the physical appeal of the solutions described in terms of the stress energy tensor patterns, which are shown to be free of singularities for model $IV$, besides admitting straightforward reductions to $(4+1)$-dimensions. In particular, from the framework of models $III$ and $IV$, one is able to achieve brane-world solutions over two different geometries of $\mathbb{S}^{2}$ which, as demonstrated, can be reduced to trivial and non-trivial extensions of the well-known $(4+1)$-dimensional brane-worlds.

hep-th↗