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Well defined quantum field theory (QFT) for the electroweak force including quantum electrodynamics (QED) and the weak force is obtained by considering natural unitary representations of a group $K\subset U(2,2)$, where $K$ is locally…

Mathematical Physics · Physics 2021-06-16 John Mashford

Spontaneous symmetry breaking has revolutionized the understanding in numerous fields of modern physics. Here, we theoretically demonstrate the spontaneous time-reversal symmetry breaking in a cavity quantum electrodynamics system in which…

Quantum Physics · Physics 2018-08-01 Yu-Kun Lu , Pai Peng , Qi-Tao Cao , Da Xu , Jan Wiersig , Qihuang Gong , Yun-Feng Xiao

The notion of scale-invariant dynamics is well established at late times in quantum chaotic systems, as illustrated by the emergence of a ramp in the spectral form factor (SFF). Building on the results of the preceding Letter [Phys. Rev.…

Statistical Mechanics · Physics 2024-01-03 Miroslav Hopjan , Lev Vidmar

In Article I, a harmonic-oscillator model of a universe of n quarks is infinitesimally modified to eliminate the background reference frame. As a result, quark trajectories exhibit the unification of gravity and the harmonic oscillator near…

High Energy Physics - Theory · Physics 2007-05-23 Marcia J. King

We study the quantum dynamics generated by the repeated action of a non-unitary evolution operator on a system of qubits. Breaking unitarity can lead to the purification of mixed initial states, which corresponds to the loss of sensitivity…

Quantum Physics · Physics 2025-12-03 Yi-Cheng Wang , Ehud Altman , Samuel J. Garratt

We apply our recently developed theory of frequency-filtered and time-resolved N-photon correlations to study the two-photon spectra of a variety of systems of increasing complexity: single mode emitters with two limiting statistics (one…

Quantum Physics · Physics 2014-03-06 A. Gonzalez-Tudela , F. P. Laussy , C. Tejedor , M. J. Hartmann , E. del Valle

Under sufficiently slow driving, thermodynamics predicts reversible evolution through a sequence of equilibrium states. We show that this expectation fails near spectral degeneracy in driven quadratic Hamiltonian systems. As the soft-mode…

Statistical Mechanics · Physics 2026-04-14 Ilki Kim

We present a multifractal analysis of time series data obtained by repeatedly running a single-qubit quantum circuit on IBM superconducting quantum computers, in which the measurement outcomes are recorded as the number of zeros. By…

Quantum Physics · Physics 2025-12-23 Mohammadreza Saghafi , Lamine Mili , Karlton Wirsing

We develop the uniform sparse Fast Fourier Transform (usFFT), an efficient, non-intrusive, adaptive algorithm for the solution of elliptic partial differential equations with random coefficients. The algorithm is an adaption of the sparse…

Numerical Analysis · Mathematics 2022-09-05 Lutz Kämmerer , Daniel Potts , Fabian Taubert

Using his formulation of the potential theoretic notion of balayage and his deep results about this idea, Beurling gave sufficient conditions for Fourier frames in terms of balayage. The analysis makes use of spectral synthesis, due to…

Functional Analysis · Mathematics 2013-09-04 Enrico Au-Yeung , John J. Benedetto

We prove that in bosonic quantum mechanics the two-point spectral form factor can be obtained as an average of the two-point out-of-time ordered correlation function, with the average taken over the Heisenberg group. In quantum field…

High Energy Physics - Theory · Physics 2019-06-19 Robert de Mello Koch , Jia-Hui Huang , Chen-Te Ma , Hendrik J. R. Van Zyl

Quantum Fourier transform is of primary importance in many quantum algorithms. In order to eliminate the destructive effects of decoherence induced by couplings between the quantum system and its environment, we propose a robust scheme for…

Quantum Physics · Physics 2007-05-23 Jian-wu Wu , Chun-wen Li , Re-bing Wu

A new type of ensemble Kalman filter is developed, which is based on replacing the sample covariance in the analysis step by its diagonal in a spectral basis. It is proved that this technique improves the aproximation of the covariance when…

Methodology · Statistics 2015-08-19 Ivan Kasanický , Jan Mandel , Martin Vejmelka

Phase-space analysis or time-frequency analysis can be thought as Fourier analysis simultaneously both in time and in frequency, originating from signal processing and quantum mechanics. On groups having unitary Fourier transform, we…

Functional Analysis · Mathematics 2020-09-21 Ville Turunen

The quantum Fourier transform (QFT) is the principal algorithmic tool underlying most efficient quantum algorithms. We present a generic framework for the construction of efficient quantum circuits for the QFT by ``quantizing'' the…

Quantum Physics · Physics 2007-05-23 Cristopher Moore , Daniel Rockmore , Alexander Russell

The presence of a dissipative environment disrupts the unitary spectrum of dynamical quantum maps. Nevertheless, key features of the underlying unitary dynamics -- such as their integrable or chaotic nature -- are not immediately erased by…

Quantum systems promise to revolutionize information processing science and technology [1-3]. The preservation of quantum coherence, the defining property of qubits, fundamentally constrains the performance of quantum information processing…

In this paper we investigate new results on the theory of superoscillations using time-frequency analysis tools and techniques such as the short-time Fourier transform (STFT) and the Zak transform. We start by studying how the short-time…

Functional Analysis · Mathematics 2024-07-18 Daniel Alpay , Antonino De Martino , Kamal Diki , Daniele C. Struppa

The exponential speedups promised by Hamiltonian simulation on a quantum computer depends crucially on structure in both the Hamiltonian $\hat{H}$, and the quantum circuit $\hat{U}$ that encodes its description. In the quest to better…

Quantum Physics · Physics 2017-07-19 Guang Hao Low , Isaac L. Chuang

We study the time dependence of the decoherence factor (DF) of a qubit globally coupled to an environmental spin system (ESS) which is driven across the quantum critical point (QCP) by varying a parameter of its Hamiltonian in time $t$ as…

Statistical Mechanics · Physics 2016-01-20 Sei Suzuki , Tanay Nag , Amit Dutta