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We quantize a homogeneous and isotropic universe for two models of modified teleparallel gravity, wherein an arbitrary function of the boundary term, namely $B$, is present in the action and in the other model a scalar field that is…

General Relativity and Quantum Cosmology · Physics 2024-05-07 H. Amiri , K. Atazadeh , H. Hadi

The quantization of gravity coupled to barotropic perfect fluid as matter field and cosmological constant is made and the wave function can be determined for any $\kappa$ in the FRW minisuperspace model. The meaning of the existence of the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 J. Socorro

The origin of cosmic structure is widely regarded as quantum, yet the Universe today appears classical. Standard lore attributes this to a "quantum-to-classical" transition on super-horizon scales during inflation. Gravity plays a central…

General Relativity and Quantum Cosmology · Physics 2026-04-03 Aurora Ireland

We study quantum cosmology with conformal matter comprising a perfect radiation fluid and a number of conformally coupled scalar fields. Focusing initially on the collective coordinates (minisuperspace) associated with homogeneous,…

High Energy Physics - Theory · Physics 2016-07-07 Steffen Gielen , Neil Turok

In quantum cosmology, one applies quantum physics to the whole universe. While no unique version and no completely well-defined theory is available yet, the framework gives rise to interesting conceptual, mathematical and physical…

General Relativity and Quantum Cosmology · Physics 2015-01-21 Martin Bojowald

We discuss FRW universe with time-dependent EoS dark fluid which leads to multiple de Sitter space. This model (as well as its scalar-tensor version) may be considered as some classical analog of cosmological landscape. The universe…

High Energy Physics - Theory · Physics 2008-11-26 Shin'ichi Nojiri , Sergei D. Odintsov

Quantum cosmology may permit to determine the initial conditions of the Universe. In particular, it may select a specific model between many possible classical models. In this work, we study a quantum cosmological model based on the string…

General Relativity and Quantum Cosmology · Physics 2009-11-10 F. G. Alvarenga , A. B. Batista , J. C. Fabris

We consider two-dimensional quantum gravity endowed with a positive cosmological constant and coupled to a conformal field theory of large and positive central charge. We study cosmological properties at the classical and quantum level. We…

High Energy Physics - Theory · Physics 2025-03-05 Dionysios Anninos , Chiara Baracco , Beatrix Mühlmann

We study a first-order formulation for the coupled evolution of a quantum scalar field and a classical Friedmann universe. The model is defined by a state dependent hamiltonian constraint and the time dependent Schr\"odinger equation for…

General Relativity and Quantum Cosmology · Physics 2021-12-20 Viqar Husain , Suprit Singh

We point out several subtleties arising in brane-world scenarios of cosmological constant cancellation. We show that solutions with curvature singularities are inconsistent, unless the contribution to the effective four-dimentional…

High Energy Physics - Theory · Physics 2009-10-31 Stefan Forste , Zygmunt Lalak , Stéphane Lavignac , Hans Peter Nilles

Quantum computers are a promising candidate to radically expand computational science through increased computing power and more effective algorithms. In particular quantum computing could have a tremendous impact in the field of quantum…

Quantum Physics · Physics 2018-12-20 Charles D. Kocher , Michael McGuigan

We discuss the hypothesis of a fixed point for quantum gravity coupled to a scalar, in the limit where the scalar field goes to infinity, accompanied by a suitable scaling of the metric. We propose that no scalar potential is present for…

High Energy Physics - Theory · Physics 2010-05-25 C. Wetterich

We study the quantum cosmology of a quadratic $f(R)$ theory with a FRW metric, via one of its equivalent Horndeski type actions, where the dynamics of the scalar field is induced. The classical equations of motion and the Weeler-deWitt…

General Relativity and Quantum Cosmology · Physics 2017-06-22 V. Vázquez-Báez , C. Ramírez

We study the classical and quantum cosmology of a 4+1-dimensional space-time with a non-zero cosmological constant coupled to a self interacting massive spinor field. We consider a spatially flat Robertson-Walker universe with the usual…

General Relativity and Quantum Cosmology · Physics 2014-11-17 B. Vakili , S. Jalalzadeh , H. R. Sepangi

We investigate a simple $f(R, T_\phi)$ gravity model coupled to a scalar field and demonstrate that the theory admits classical degenerate metric solutions, analogous to those known in general relativity. In particular, we identify a class…

General Relativity and Quantum Cosmology · Physics 2026-03-10 Serkan Doruk Hazinedar , Yaghoub Heydarzade

We present exact quantum solutions for a noncommutative, multidimensional cosmological model and show that stabilization of extra dimensions sets in with the introduction of noncommutativity between the scale factors. An interpretation is…

General Relativity and Quantum Cosmology · Physics 2008-11-26 N. Khosravi , S. Jalalzadeh , H. R. Sepangi

The problem of the physical nature and the cosmological constant genesis is discussed. This problem can't be solved in terms of the current quantum field theory which operates with Higgs and nonperturbative vacuum condensates and takes into…

Astrophysics · Physics 2007-05-23 Vladimir Burdyuzha , Olga Lalakulich , Yuri Ponomarev , Grigory Vereshkov

We study the classical-quantum (CQ) hybrid dynamics of homogeneous cosmology from a Hamiltonian perspective where the classical gravitational phase space variables and matter state evolve self-consistently with full backreaction. We compare…

General Relativity and Quantum Cosmology · Physics 2024-02-23 Viqar Husain , Muhammad Muzammil

We look for exact solutions in scalar field cosmology. To achieve this we use $f(R)$ modified gravity with a scalar field and do not specify the the form of the $f(R)$ function. In particular, we study Friedmann universe assuming that…

General Relativity and Quantum Cosmology · Physics 2017-09-14 S. D. Maharaj , R. Goswami , S. V. Chervon , A. V. Nikolaev

We consider a four-dimensional flat-space Friedman universe, which is filled with two interacting ideal fluids (the coupling of dark energy with dark matter of special form). The gravitational equations of motion are solved. It is shown…

High Energy Physics - Theory · Physics 2009-09-07 A. V. Timoshkin