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The effective quantum dynamics of Bianchi I spacetime is addressed within the statistical regularization scheme in Quantum Reduced Loop Gravity. The case of a minimally coupled massless scalar field is studied and compared with the…

General Relativity and Quantum Cosmology · Physics 2019-05-29 Emanuele Alesci , Gioele Botta , Giovanni Luzi , Gabriele V. Stagno

We study homogeneous cosmological models in formulations of general relativity with cosmological constant based on a (complexified) connection rather than a spacetime metric, in particular in a first order theory obtained by integrating out…

General Relativity and Quantum Cosmology · Physics 2023-05-10 Steffen Gielen , Elliot Nash

Quantum computing has the potential to reduce the computational cost required for quantum dynamics simulations. However, existing quantum algorithms for coupled electron-nuclear dynamics simulation either require fault-tolerant devices, or…

Quantum Physics · Physics 2026-03-03 Jong-Kwon Ha , Ryan J. MacDonell

We present a new cosmological model derived from Loop Quantum Gravity. The formulation is based on a projection of the kinematical Hilbert space of the full theory down to a subspace representing the proper arena for an inhomogeneous…

General Relativity and Quantum Cosmology · Physics 2015-06-11 Emanuele Alesci , Francesco Cianfrani

The asymptotic behaviour of vacuum Bianchi models of class A near the initial singularity is studied, in an effort to confirm the standard picture arising from heuristic and numerical approaches by mathematical proofs. It is shown that for…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Alan D. Rendall

We provide a quantum picture for the emergence of a bouncing cosmology, according to the idea that a semiclassical behavior of the Universe towards the singularity is not available in many relevant Minisuperspace models. In particular, we…

General Relativity and Quantum Cosmology · Physics 2022-09-07 Eleonora Giovannetti , Giovanni Montani

We describe the quantum evolution of the vacuum Bianchi II universe in terms of the transition amplitude between two asymptotic quantum Kasner-like states. For large values of the momentum variable the classical and quantum calculations…

General Relativity and Quantum Cosmology · Physics 2015-06-19 Hervé Bergeron , Orest Hrycyna , Przemysław Małkiewicz , Włodzimierz Piechocki

The nature of cosmological solutions for a homogeneous, anisotropic Universe given by a Bianchi type-I (BI) model in the presence of a Cosmological constant $\Lambda$ is investigated by taking into account dissipative process due to…

General Relativity and Quantum Cosmology · Physics 2015-05-01 Bijan Saha , V. Rikhvitsky

We discuss a symmetry-adapted algebraic (or vibron) model for molecular spectroscopy. The model is formulated in terms of tensor operators under the molecular point group. In this way, we have identified interactions that are absent in…

Chemical Physics · Physics 2017-11-02 R. Bijker , A. Frank , R. Lemus , J. M. Arias , F. Perez-Bernal

We implement the no-boundary proposal for the wave function of the universe in an exactly solvable Bianchi IX minisuperspace model with two scale factors. We extend our earlier work (Phys. Rev. Lett. 121, 081302, 2018 / arXiv:1804.01102) to…

General Relativity and Quantum Cosmology · Physics 2019-07-03 Oliver Janssen , Jonathan J. Halliwell , Thomas Hertog

The Bianchi IX cosmological model in vacuum can be represented by several six-dimensional dynamical systems. In one of them we present a new closed form solution expressed by a third Painleve' function.

Exactly Solvable and Integrable Systems · Physics 2014-06-26 Robert Conte

We propose a mixed-configuration approximation based on single-band impurity solvers to efficiently study nonequilibrium multi-orbital systems at moderate computational cost. In this work, we merge the approach with the so-called auxiliary…

Strongly Correlated Electrons · Physics 2025-07-16 Tommaso Maria Mazzocchi , Daniel Werner , Markus Aichhorn , Enrico Arrigoni

Two physically important potentials (Manning-Rosen and P\"oschl-Teller) are considered for the ro-vibrational energy in diatomic molecules. An improved new approximation is invoked for the centrifugal term, which is then used for their…

Quantum Physics · Physics 2022-05-23 Debraj Nath , Amlan K. Roy

Deviations from statistical isotropy can be modeled in various ways, for instance, anisotropic cosmological models (Bianchi models), compact topologies and presence of primordial magnetic field. Signature of anisotropy manifests itself in…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-12 Nidhi Joshi , Sanjay Jhingan , Tarun Souradeep , Amir Hajian

Using a qualitative analysis based on the Hamiltonian formalism and the orthonormal frame representation we investigate whether the chaotic behaviour which occurs close to the initial singularity is still present in the far future of…

General Relativity and Quantum Cosmology · Physics 2009-11-07 John D. Barrow , Yves Gaspar

The framework of quantum symmetry reduction is applied to loop quantum gravity with respect to transitively acting symmetry groups. This allows to test loop quantum gravity in a large class of minisuperspaces and to investigate its features…

General Relativity and Quantum Cosmology · Physics 2010-11-19 Martin Bojowald

The standard cosmological model is challenged by an ever-growing collection of observations, which invites (and stimulates) inquiry into possible additions and/or alterations. One such alteration comes from letting cosmic isotropy -- as…

General Relativity and Quantum Cosmology · Physics 2026-04-22 Robbert W. Scholtens , Marcello Seri , Holger Waalkens , Rien van de Weygaert

Vacuum polarization of the quantized massive fields in Bianchi type I spacetime is investigated from the point of view of the adiabatic approximation and the Schwinger-DeWitt method. It is shown that both approaches give the same results…

General Relativity and Quantum Cosmology · Physics 2018-12-05 Jerzy Matyjasek

Expansion of a locally equilibrated fluid is considered in an anisotropic space-time given by Bianchi type I metric. Starting from isotropic equilibrium phase-space distribution function in the local rest frame, we obtain expressions for…

General Relativity and Quantum Cosmology · Physics 2018-05-08 Ashutosh Dash , Amaresh Jaiswal

We present an extension of the Hamiltonian of the two dimensional limit of the vibron model encompassing all possible interactions up to four-body operators. We apply this Hamiltonian to the modeling of the experimental bending spectrum of…

Chemical Physics · Physics 2021-03-17 Jamil Khalouf-Rivera , Francisco Pérez-Bernal , Miguel Carvajal