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A defining feature in the field of quantum computing is the potential of a quantum device to outperform its classical counterpart for a specific computational task. By now, several proposals exist showing that certain sampling problems can…

Quantum Physics · Physics 2020-09-23 Rawad Mezher , Joe Ghalbouni , Joseph Dgheim , Damian Markham

We discuss Cosmic Microwave Background constraints on the causal set theory of quantum gravity, which has made testable predictions about the nature of dark energy. We flesh out previously discussed heuristic constraints by showing how the…

Astrophysics · Physics 2008-11-26 Joe Zuntz

Quantifying the complexity of quantum states that possess intrinsic structure, such as symmetry or encoding, in a fair manner constitutes a core challenge in the benchmarking of quantum technologies. This paper introduces the…

Quantum Physics · Physics 2025-12-30 HongZheng Liu , YiNuo Tian , Zhiyue Wu

$Circuit~ Complexity$, a well known computational technique has recently become the backbone of the physics community to probe the chaotic behaviour and random quantum fluctuations of quantum fields. This paper is devoted to the study of…

We present a quantum calculation based on scattering theory of the frequency dependent noise of current in an interacting chaotic cavity. We include interactions of the electron system via long range Coulomb forces between the conductor and…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 F. W. J. Hekking , J. P. Pekola

A quantum critical system described at low energy by a conformal field theory (CFT) and subjected to a time-periodic boundary drive displays multiple dynamical regimes depending on the drive frequency. We compute the behavior of quantities…

Strongly Correlated Electrons · Physics 2017-07-03 William Berdanier , Michael Kolodrubetz , Romain Vasseur , Joel E. Moore

We investigate the Cherenkov radiation triggered by qubit acceleration simulated by superconducting circuit. By analyzing the radiation probability, we confirm the existence of Cherenkov speed threshold, implying that simulating…

Quantum Physics · Physics 2021-09-06 Jhen-Dong Lin , Yueh-Nan Chen

Causality testing, the act of determining cause and effect from measurements, is widely used in physics, climatology, neuroscience, econometrics and other disciplines. As a result, a large number of causality testing methods based on…

Data Analysis, Statistics and Probability · Physics 2018-02-20 Aditi Kathpalia , Nithin Nagaraj

We derive bounds on couplings in the standard model effective field theory (SMEFT) as a consequence of causality and the analytic structure of scattering amplitudes. In the SMEFT, there are 64 independent operators at mass dimension eight…

High Energy Physics - Phenomenology · Physics 2020-09-16 Grant N. Remmen , Nicholas L. Rodd

The entanglement entropy (EE) of quantum systems is often used as a test of low-energy descriptions by conformal field theory (CFT). Here we point out that this is not a reliable indicator, as the EE often shows the same behavior even when…

Strongly Correlated Electrons · Physics 2017-08-02 Pranay Patil , Ying Tang , Emanuel Katz , Anders W. Sandvik

This paper explores the connection between causality and many-body dynamics by studying the algebraic structure of tri-partite unitaries ('walls') which permanently arrest local operator spreading in their time-periodic evolution. We show…

Quantum Physics · Physics 2026-02-09 Marcell D. Kovács , Christopher J. Turner , Lluís Masanes

In this paper we continue to explore "hybrid" quantum circuit models in one-dimension with both unitary and measurement gates, focussing on the entanglement properties of wavefunction trajectories at long times, in the steady state. We…

Statistical Mechanics · Physics 2023-08-23 Yaodong Li , Xiao Chen , Matthew P. A. Fisher

We compute the two-loop effective field theory (EFT) power spectrum of dark matter density fluctuations in $\Lambda$CDM using the recently proposed COBRA method (Bakx. et al, 2025). With COBRA, we are able to evaluate the two-loop matter…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-11 Thomas Bakx , Henrique Rubira , Nora Elisa Chisari , Zvonimir Vlah

We present QEst, a procedure to systematically generate approximations for quantum circuits to reduce their CNOT gate count. Our approach employs circuit partitioning for scalability with procedures to 1) reduce circuit length using…

Quantum Physics · Physics 2021-08-31 Tirthak Patel , Ed Younis , Costin Iancu , Wibe de Jong , Devesh Tiwari

We explore the constraints imposed on higher curvature corrections of the Lovelock type due to causality restrictions in the boundary of asymptotically AdS space-time. In the framework of AdS/CFT, this is related to positivity of the energy…

High Energy Physics - Theory · Physics 2014-11-20 Xian O. Camanho , Jose D. Edelstein

Coherent errors, and especially those that occur in correlation among a set of qubits, are detrimental for large-scale quantum computing. Correlations in noise can occur as a result of spatial and temporal configurations of instructions…

The causal entropy bound (CEB) is confronted with recent explicit entropy calculations in weakly and strongly coupled conformal field theories (CFTs) in arbitrary dimension $D$. For CFT's with a large number of fields, $N$, the CEB is found…

High Energy Physics - Theory · Physics 2009-11-07 R. Brustein , S. Foffa , G. Veneziano

Causality in a shockwave state is related to the analytic properties of a four-point correlation function. Extending recent results for scalar probes, we show that this constrains the couplings of the stress tensor to light spinning…

High Energy Physics - Theory · Physics 2018-06-20 Thomas Hartman , Sachin Jain , Sandipan Kundu

We map out the critical velocity in the crossover from Bose-Einstein condensation (BEC) to Bardeen-Cooper-Schrieffer superfluidity with ultracold $^{6}$Li gases. A small attractive potential is dragged along lines of constant column…

We introduce two new effective quantities for the study of comoving curvature perturbations $\zeta$: the space dependent effective sound speed (SESS) and the momentum dependent effective sound speed (MESS) . We use the SESS and the MESS to…

General Relativity and Quantum Cosmology · Physics 2018-08-28 Antonio Enea Romano , Sergio A. Vallejo Pena