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In this contribution we sketch a branch-cut quantum formulation of the Wheeler-DeWitt equation analytically continued to the complex plane. As a starting point, we base our approach on the Ho\v{r}ava-Lifshitz formulation of gravity, which…

General Relativity and Quantum Cosmology · Physics 2022-12-08 Peter O. Hess , César A. Zen Vasconcellos , José de Freitas Pacheco , Dimiter Hadjimichef , Benno Bodmann

We analyze squeezing of the nanoresonator state produced by periodic measurement of position by a quantum point contact or a single-electron transistor. The mechanism of squeezing is the stroboscopic quantum nondemolition measurement…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Rusko Ruskov , Keith Schwab , Alexander N. Korotkov

We report recent progress on the phase space formulation of quantum mechanics with coordinate-momentum variables, focusing more on new theory of (weighted) constraint coordinate-momentum phase space for discrete-variable quantum systems.…

Quantum Physics · Physics 2022-05-18 Xin He , Baihua Wu , Youhao Shang , Bingqi Li , Xiangsong Cheng , Jian Liu

In this paper, we consider the Universe at the late stage of its evolution and deep inside the cell of uniformity. At these scales, we can consider the Universe to be filled with dust-like matter in the form of discretely distributed…

General Relativity and Quantum Cosmology · Physics 2016-08-02 Mariam Bouhmadi-López , K. Sravan Kumar , João Marto , João Morais , Alexander Zhuk

A novel approach to the class of cosmic barotropic fluids in which the speed of sound squared is defined as a function of the Equation of State parameter, so called $c_s^2(w)$ models, is examined. For this class of models, a new analytical…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-03 Dalibor Perkovic , Hrvoje Stefancic

In quantum physics, the density operator completely describes the state. Instead, in classical physics the mean value of every physical quantity is evaluated by means of a probability distribution. We study the possibility to describe pure…

Quantum Physics · Physics 2011-11-09 Alberto Montina

It is well-known that quantum field theory (QFT) induces a huge value of the cosmological constant, $\Lambda$, which is outrageously inconsistent with cosmological observations. We review here some aspects of this fundamental theoretical…

General Relativity and Quantum Cosmology · Physics 2022-07-19 Joan Sola Peracaula

The degrees of quantum coherence of cosmological perturbations of different spins are computed in the large-scale limit and compared with the standard results holding for a single mode of the electromagnetic field in an optical cavity. The…

General Relativity and Quantum Cosmology · Physics 2017-11-09 Massimo Giovannini

We previously showed that we can use di quark pairs as a model of how nucleation of a new universe occurs. We now can construct a model showing evolution from a dark matter dark energy mix to a pure cosmological constant cosmology due to…

General Relativity and Quantum Cosmology · Physics 2007-05-23 A. W. Beckwith

K-essence models, relying on scalar fields with non-canonical kinetic terms, have been proposed as an alternative to quintessence in explaining the observed acceleration of the Universe. We consider the use of field redefinitions to cast…

Astrophysics · Physics 2011-06-21 Michael Malquarti , Edmund J Copeland , Andrew R Liddle , Mark Trodden

We theoretically study the quantum speed limit of a single atom trapped in a Fabry-Perot microresonator. The cavity mode will be squeezed when a driving laser is applied to the second-order nonlinear medium, and the effective Hamiltonian…

Quantum Physics · Physics 2023-10-25 Ya-Jie Ma , Xue-Chen Gao , Shao-Xiong Wu , Chang-shui Yu

We develop a quantum-cosmological framework in which the inflationary potential emerges from the structure of the wave function of the universe rather than being postulated. Starting from the Wheeler-DeWitt equation for a flat…

General Relativity and Quantum Cosmology · Physics 2025-10-07 Gerasimos Kouniatalis

Building upon our recently established correspondence between quantum cosmology and the hydrogen atom [1], we investigate the specific sector of a negative cosmological constant ($\Lambda < 0$) in a flat FLRW universe with dust. While the…

General Relativity and Quantum Cosmology · Physics 2026-01-29 Dipayan Mukherjee , Harkirat Singh Sahota , S. Shankaranarayanan

In this paper, the Higgs-like approach is used to analyze the quantum dynamics of a harmonic oscillator constrained on a circle. We obtain the Hamiltonian of this system as a function of the Cartesian coordinate of the tangent line through…

Quantum Physics · Physics 2022-07-27 Ali Mahdifar , Ehsan Amooghorban

We propose a method to achieve quantum supremacy using ensembles of qubits, using only spin squeezing, basis rotations, and Fock state measurements. Each ensemble is assumed to be controllable only with its total spin. Using a repeated…

Quantum Physics · Physics 2022-04-26 Yueheng Shi , Junheng Shi , Tim Byrnes

The dynamics of the expanding universe is analyzed in terms of the quantum geometrodynamical model. It is shown that the equations of quantum theory in the form of the eigenvalues equation similar to the stationary Schr\"{o}dinger equation…

General Relativity and Quantum Cosmology · Physics 2013-11-22 V. E. Kuzmichev , V. V. Kuzmichev

We construct cosmological models based on a complex scalar field with a power-law potential $V=\frac{K}{\gamma-1}(\frac{m}{\hbar})^{2\gamma}|\varphi|^{2\gamma}$ associated with a polytropic equation of state $P=K\rho^{\gamma}$ (the…

General Relativity and Quantum Cosmology · Physics 2022-08-17 Pierre-Henri Chavanis

We study operator complexity on various time scales with emphasis on those much larger than the scrambling period. We use, for systems with a large but finite number of degrees of freedom, the notion of K-complexity employed in…

High Energy Physics - Theory · Physics 2020-01-08 J. L. F. Barbon , E. Rabinovici , R. Shir , R. Sinha

Optimal phase estimation of a phase-squeezed quantum state of light has been recently shown to beat the coherent-state limit. Here, the estimation is made robust to uncertainties in underlying parameters using a robust fixed-interval…

Quantum Physics · Physics 2015-09-14 Shibdas Roy , Ian R. Petersen , Elanor H. Huntington

Quantum computational complexity estimates the difficulty of constructing quantum states from elementary operations, a problem of prime importance for quantum computation. Surprisingly, this quantity can also serve to study a completely…

High Energy Physics - Theory · Physics 2022-03-02 Shira Chapman , Giuseppe Policastro
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