English
Related papers

Related papers: Polymer dynamics of isotropic universe in Ashtekar…

200 papers

We implement Polymer Quantum Mechanics on the Hamiltonian formulation of the isotropic Universe in both the representations of the standard Ashtekar-Barbero-Immirzi connection and of a new generalized coordinate conjugate to the Universe…

General Relativity and Quantum Cosmology · Physics 2023-02-01 Gabriele Barca , Eleonora Giovannetti , Federico Mandini , Giovanni Montani

We analyze the Bianchi I cosmology in the presence of a massless scalar field and describe its dynamics via a semiclassical and quantum polymer approach. We study the morphology of the Big Bounce by adopting three different sets of…

General Relativity and Quantum Cosmology · Physics 2022-03-09 E. Giovannetti , G. Montani , S. Schiattarella

We analyze the Bianchi I cosmology in the presence of a massless scalar field and describe its dynamics via a semiclassical and quantum polymer approach. We investigate the morphology of the emerging Big Bounce by adopting three different…

General Relativity and Quantum Cosmology · Physics 2022-03-10 Eleonora Giovannetti , Giovanni Montani , Silvia Schiattarella

We analyse the semi-classical and quantum dynamics of the isotropic Universe in the framework of the Polymer Quantum mechanics, in order to implement a cut-off physics on the initial singularity. We first identify in the Universe cubed…

General Relativity and Quantum Cosmology · Physics 2019-03-29 Giovanni Montani , Claudia Mantero , Flavio Bombacigno , Francesco Cianfrani , Gabriele Barca

We construct the Hamiltonian formulation of the isotropic Universe in a generic metric f(R)-theory in the Jordan frame. We canonically quantize the Universe volume via a polymer formulation, and we adopt the scalar field naturally arising…

General Relativity and Quantum Cosmology · Physics 2026-01-26 M. L. Limongi , S. Lo Franco , G. Montani , S. Segreto

We present a review on basic aspects of quantum cosmology in the presence of cut-off physics. We first analyze how the Wheeler-DeWitt equation in a pure metric approach describes the quantum Universe, showing how the singularity is not…

General Relativity and Quantum Cosmology · Physics 2021-09-20 Gabriele Barca , Eleonora Giovannetti , Giovanni Montani

We investigate the classical and quantum behavior of a Bianchi I model in the presence of a stiff matter contribution when the Vilenkin interpretation of the wave function of the Universe is taken into account. We study its evolution in the…

General Relativity and Quantum Cosmology · Physics 2017-08-02 Riccardo Moriconi , Giovanni Montani

We study the implementation of Polymer Quantum Mechanics (PQM) to a system decomposed into a quasi-classical background and a small quantum subsystem, according to the original Vilenkin proposal. We develop the whole formalism in the…

General Relativity and Quantum Cosmology · Physics 2023-09-15 Eleonora Giovannetti , Giovanni Montani

The Immirzi parameter is promoted to be a scalar field and the Hamiltonian analysis of the corresponding dynamical system is performed in the presence of gravity. We identified some SU(2) connections, generalizing Ashtekar-Barbero…

General Relativity and Quantum Cosmology · Physics 2016-09-14 Flavio Bombacigno , Francesco Cianfrani , Giovanni Montani

We analyze the semiclassical polymer dynamics of the inhomogeneous Mixmaster model by choosing the cubed scale factor as the discretized configurational variable, while the anisotropies remain pure Einsteinian variables. Such a modified…

General Relativity and Quantum Cosmology · Physics 2019-02-06 Stefano Antonini , Giovanni Montani

We investigate the emergence of a quantum Big-Bounce in the context of an isotropic Universe, filled by a self-interacting scalar field, which plays the role of a physical clock. The bouncing cosmology is the result of a scattering process,…

General Relativity and Quantum Cosmology · Physics 2024-10-04 S. Lo Franco , G. Montani

The absence of isotropic singularity in loop quantum cosmology can be understood in an effective classical description as the universe exhibiting a Big Bounce. We show that with scalar matter field, the big bounce is generic in the sense…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Ghanashyam Date , Golam Mortuza Hossain

We analyze the canonical quantum dynamics of the isotropic Universe in a metric approach by adopting a self-interacting scalar field as relational time. When the potential term is absent we are able to associate the the expanding and…

General Relativity and Quantum Cosmology · Physics 2023-09-15 Eleonora Giovannetti , Fabio Maione , Giovanni Montani

We analyze the Bianchi IX Universe in the Polymer Quantum Mechanics framework by facing both semiclassical and purely quantum effects near the cosmological singularity. We adopt Misner variables to describe the model dynamics, applying the…

General Relativity and Quantum Cosmology · Physics 2019-12-03 Eleonora Giovannetti , Giovanni Montani

We analyze some relevant semiclassical and quantum features of the implementation of Polymer Quantum Mechanics to the phenomenology of the flat isotropic Universe. We firstly investigate a parallelism between the semiclassical polymer…

General Relativity and Quantum Cosmology · Physics 2020-04-17 Gabriele Barca , Paolo Di Antonio , Giovanni Montani , Alberto Patti

We analyze the dynamics of the Bianchi I model in the presence of stiff matter, an ultrarelativistic component and a small negative cosmological constant. We quantize this model in the framework of the polymer quantum mechanics, in order to…

General Relativity and Quantum Cosmology · Physics 2018-05-16 Giovanni Montani , Andrea Marchi , Riccardo Moriconi

We construct and study Loop Quantum Cosmology (LQC) when the Barbero-Immirzi parameter takes the complex value $\gamma=\pm i$. We refer to this new quantum cosmology as complex Loop Quantum Cosmology. We proceed in making an analytic…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Jibril Ben Achour , Julien Grain , Karim Noui

In homogeneous and isotropic loop quantum cosmology, gravity can behave repulsively at Planckian energy densities leading to the replacement of the big bang singularity with a big bounce. Yet in any bouncing scenario it is important to…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Dah-Wei Chiou , Kevin Vandersloot

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 analyze the semiclassical and quantum behavior of the Bianchi IX Universe in the Polymer Quantum Mechanics framework, applied to the isotropic Misner variable, linked to the space volume of the model. The study is performed both in the…

General Relativity and Quantum Cosmology · Physics 2018-11-06 Chiara Crinò , Giovanni Montani , Giorgio Pintaudi
‹ Prev 1 2 3 10 Next ›