English
Related papers

Related papers: Complex Lagrangians and phantom cosmology

200 papers

We investigate the static and spherically symmetric solutions of Einstein's equations for a scalar field with non-canonical kinetic term, assumed to provide both the dark matter and dark energy components of the Universe. In particular, we…

Astrophysics · Physics 2008-11-26 Daniele Bertacca , Nicola Bartolo , Sabino Matarrese

The purpose of this paper is to introduce a new way to inquire the quantum cosmology for a certain gravitational theory. Normally, the quantum cosmological model is introduced as the minisuperspace theory which is obtained by reducing the…

General Relativity and Quantum Cosmology · Physics 2016-06-07 Miao He , Zi-Liang Wang , Jian-Bo Deng , Hua Chen

In this paper we introduce a geometric description of Lagrangian and Hamiltonian classical field theories on Lie algebroids in the framework of $k$-cosymplectic geometry. We discuss the relation between Lagrangian and Hamiltonian…

Mathematical Physics · Physics 2023-08-03 D. Martin de Diego , S. Vilariño

A survey of topics of recent interest in Hamiltonian and Lagrangian dynamical systems, including accessible discussions of regularization of the central force problem; inequivalent Lagrangians and Hamiltonians; constants of central force…

Classical Physics · Physics 2009-11-11 James T. Wheeler

This paper gives both a general canonical quantum gravity theory and the general canonical quantum gravity theories of the Universe and general black hole, and discovers the relations reflecting symmetric properties of the standard…

General Physics · Physics 2021-11-19 C. Huang , Yong-Chang Huang , Xinfei Li

It is proposed that the current acceleration of the universe is not originated by the existence of a mysterious dark energy fluid nor by the action of extra terms in the gravity Lagrangian, but just from the sub-quantum potential associated…

High Energy Physics - Theory · Physics 2010-12-13 Pedro F. Gonzalez-Diaz

We investigate hidden symmetries in minimally coupled scalar field cosmology within the FLRW universe, and a perfect fluid with and without interaction to the scalar field. We show that for an exponential potential there exists a set of…

General Relativity and Quantum Cosmology · Physics 2025-12-25 Andronikos Paliathanasis

The non-Hermitian Schr\"odinger equation is re-expressed generally in the form of Hamilton's canonical equation without any approximation. Its quantization called non-Hermitian quantum field theory is discussed. By virtue of the canonical…

Quantum Physics · Physics 2020-05-22 Qi Zhang

Based on an identified quantum relativity symmetry the contraction of which gives the Newtonian approximation of Galilean relativity, a quantum model of the physical space can be formulated with the Newtonian space seen in a way as the…

Quantum Physics · Physics 2019-03-27 Otto C. W. Kong

Non-Hermitian quantum field theories are a promising tool to study open quantum systems. These theories preserve unitarity if PT-symmetry is respected, and in that case an equivalent Hermitian description exists via the so-called Dyson map.…

High Energy Physics - Theory · Physics 2024-11-28 Daniel Arean , David Garcia-Fariña , Karl Landsteiner

We present numerical $N$-body simulation studies of large-scale structure formation. The main purpose of these studies is to analyze the several models of dark matter and the role they played in the process of large-scale structure…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-22 M. A. Rodriguez-Meza

We develop a systematic classical framework to accommodate canonical quantization of geometric and matter perturbations on a quantum homogeneous isotropic flat spacetime. The existing approach of standard cosmological perturbations is…

General Relativity and Quantum Cosmology · Physics 2013-06-05 Andrea Dapor , Jerzy Lewandowski , Jacek Puchta

The redistribution of energy levels between energy bands is studied for a family of simple effective Hamiltonians depending on one control parameter and possessing axial symmetry and energy-reflection symmetry. Further study is made on the…

Quantum Physics · Physics 2017-07-14 Guillaume Dhont , Toshihiro Iwai , Boris Zhilinskii

We introduce a new model of background independent physics in which the degrees of freedom live on a complete graph and the physics is invariant under the permutations of all the points. We argue that the model has a low energy phase in…

High Energy Physics - Theory · Physics 2007-05-23 Tomasz Konopka , Fotini Markopoulou , Lee Smolin

Theories described by non-Hermitian Hamiltonians are known to possess strictly positive energy eigenvalues and exhibit unitary time evolution if the Hamiltonian is symmetric under discrete parity and time (PT) transformation. In this work,…

High Energy Physics - Theory · Physics 2025-08-04 Jeffrey Kuntz

The energy density of the universe today may be dominated by the vacuum energy of a slowly rolling scalar field. Making a quantum expansion around such a time dependent solution is found to break fundamental symmetries of quantum field…

High Energy Physics - Phenomenology · Physics 2008-11-26 Pankaj Jain , Subhadip Mitra

In arXiv:1601.02203 and arXiv:1702.07063, we have proposed a topological model with a simple Lagrangian density and have tried to solve one of the cosmological constant problems. The Lagrangian density is the BRS exact and therefore the…

High Energy Physics - Theory · Physics 2018-02-14 Shin'ichi Nojiri

We formulate the notion of quantum group symmetry of the Hamiltonian corresponding to Potts model and compute it for few simple models. Our examples illustrate how a slight change of the model parameter may result in a drastic change of the…

Quantum Algebra · Mathematics 2023-02-20 Debashish Goswami , Sk Asfaq Hossain

The classical Hamilton equations of motion yield a structure sufficiently general to handle an almost arbitrary set of ordinary differential equations. Employing elementary algebraic methods, it is possible within the Hamiltonian structure…

Classical Physics · Physics 2008-07-30 B. Aycock , A. Roe , J. L. Silverberg , A. Widom

Classical and quantum mechanical descriptions of physical world are seamlessly abridged within the framework of Lagrangian formalism which, besides revealing the essence of nonlocally correlated dynamic evolution, helps understanding abrupt…

Classical Physics · Physics 2024-10-04 D Das