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We show that a quantum subsystem can become significantly entangled with a classical background through a process with little or none semi-classical back-reactions. We study two quantum harmonic oscillators coupled to each other in a…

High Energy Physics - Theory · Physics 2017-07-19 I-Sheng Yang

Simple classical mechanical systems and solution spaces of classical field theories involve singularities. In certain situations these singularities can be understood in terms of stratified Kaehler spaces. We give an overview of a research…

Mathematical Physics · Physics 2007-05-23 Johannes Huebschmann

We consider the interpretation in classical geometry of conformal field theories constructed from orbifolds with discrete torsion. In examples we can analyze, these spacetimes contain ``stringy regions'' that from a classical point of view…

High Energy Physics - Theory · Physics 2010-04-07 Cumrun Vafa , Edward Witten

In this paper, we are exploring some of the properties of the self-similar solutions of the first kind. In particular, we shall discuss the kinematic properties and also check the singularities of these solutions. We discuss these…

General Relativity and Quantum Cosmology · Physics 2009-11-10 M. Sharif , Sehar Aziz

We analyse the classical and quantum theory of a scalar field interacting with gravitation in two dimensions. We describe a class of analytic solutions to the Wheeler-DeWitt equation from which we are able to synthesise states that give…

General Relativity and Quantum Cosmology · Physics 2010-04-06 M Onder , R W Tucker

These lecture notes attempt to invite the reader towards the theory of singular foliations, both smooth and holomorphic. In addition to a systematic review of the foundations, and an attempt to put in order examples and several elementary…

Differential Geometry · Mathematics 2024-11-21 Camille Laurent-Gengoux , Ruben Louis , Leonid Ryvkin

Recent developments in observational cosmology call for understanding the nature of the cosmological singularity (CS). Our work proposes modelling the vicinity of CS by a time dependent orbifold (TDO). Our model makes sense if quantum…

General Relativity and Quantum Cosmology · Physics 2010-02-26 Przemyslaw Malkiewicz

In this letter, we consider cosmological solutions of bimetric theory without assuming that only one metric is coupled to gravity. We conclude that any cosmology can be described by fixing the matter content of the space that we are not…

General Relativity and Quantum Cosmology · Physics 2013-01-21 Salvatore Capozziello , Prado Martin-Moruno

Two dimensional classical string theory is solved in any curved spacetime. The complete spacetime required to describe the classical string motions turns out to be larger than the global space required by complete particle geodesics. The…

High Energy Physics - Theory · Physics 2008-02-03 Itzhak Bars

The expression for the variation of the area functional of the second fundamental form of a hypersurface in a Euclidean space involves the so-called "mean curvature of the second fundamental form". Several new characteristic properties of…

Differential Geometry · Mathematics 2009-09-18 Steven Verpoort

A spherical conical metric $g$ on a surface $\Sigma$ is a metric of constant curvature $1$ with finitely many isolated conical singularities. The uniformization problem for such metrics remains largely open when at least one of the cone…

Differential Geometry · Mathematics 2021-04-22 Mikhail Karpukhin , Xuwen Zhu

In this letter we show that communication when restricted to a single information carrier (i.e. single particle) and finite speed of propagation is fundamentally limited for classical systems. On the other hand, quantum systems can surpass…

Quantum Physics · Physics 2018-02-22 Flavio Del Santo , Borivoje Dakić

A recent work [Phys. Rev. D 111, 104040] shows that the curvature singularity of a black hole can vanish at a fine-tuned mass value, which implies that regular black holes could be special states in black hole evolution. We study the…

General Relativity and Quantum Cosmology · Physics 2025-05-19 Xiao-Pin Rao , Hyat Huang

In this paper, the theory of functions of one complex variable is explored to study linearly full unramified holomorphic two-spheres with constant curvature in $G(2,n)$ satisfying that the generated harmonic sequence degenerates at position…

Differential Geometry · Mathematics 2020-03-06 Jie Fei , Ling He

I investigate spacetime singularities from the point of view of the wavefunction of the universe. In order to extend the classical notion of geodesic incompleteness one has to include the proper time of an observer as a degree of freedom in…

General Relativity and Quantum Cosmology · Physics 2025-11-14 Federico Piazza

It is demonstrated that the collapse of the wave function is equivalent to the continuity of measurement outcomes. The latter states that a second measurement has to result in the same outcome as the first measurement of the same observable…

Quantum Physics · Physics 2018-06-01 J. Sperling

Correspondence between classical periodic orbits and quantum shell structure is investigated for a reflection-asymmetric deformed oscillator model as a function of quadrupole and octupole deformation parameters. Periodic orbit theory…

Nuclear Theory · Physics 2009-10-28 Ken-ichiro Arita , Kenichi Matsuyanagi

This paper presents two unconventional links between quantum and classical physics. The first link appears in the study of quantum cryptography. In the presence of a spy, the quantum correlations shared by Alice and Bob are imperfect. One…

Quantum Physics · Physics 2007-05-23 Valerio Scarani

Since the beginning of quantum mechanics, many puzzling phenomena which distinguish the quantum from the classical world, have appeared such as complementarity, entanglement or contextuality. All of these phenomena are based on the…

Quantum Physics · Physics 2016-11-24 S. Wölk

Hilbert bimodules are morphisms between C*-algebraic models of quantum systems, while symplectic dual pairs are morphisms between Poisson geometric models of classical systems. Both of these morphisms preserve representation-theoretic…

Mathematical Physics · Physics 2024-05-01 Benjamin H. Feintzeig , Jer Steeger