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Treatment effects can be estimated from observational data as the difference in potential outcomes. In this paper, we address the challenge of estimating the potential outcome when treatment-dose levels can vary continuously over time.…

Machine Learning · Statistics 2017-11-07 Hossein Soleimani , Adarsh Subbaswamy , Suchi Saria

The outcome of continuously measuring a quantum system is a string of data whose intricate correlation properties reflect the underlying quantum dynamics. In this paper we study the role of these correlation in reconstructing the…

Quantum Physics · Physics 2024-11-14 Joseph A. Smiga , Gabriel T. Landi

Quantum materials hold immense promises for future applications due to their intriguing electronic, magnetic, thermal, and mechanical properties that often arise from a complex interplay between microscopic degrees of freedom. Important…

Strongly Correlated Electrons · Physics 2025-02-18 Chenhang Xu , Alfred Zong

The mismatch between elegant theoretical models and the detailed experimental reality is particularly pronounced in quantum nonlinear interferometry (QNI). In stark contrast to theory, experiments contain pump beams that start in impure…

Quantum Physics · Physics 2022-11-23 Paul Kinsler , Martin W. McCall , Rupert F. Oulton , Alex S. Clark

Most material properties of great physical interest are directly related to nuclear dynamics, e.g. the ionic thermal conductivity, Raman/IR vibrational spectra, inelastic X-ray, and Neutron scattering. A theory able to compute from first…

Statistical Mechanics · Physics 2021-03-31 Lorenzo Monacelli , Francesco Mauri

We show that time-correlation functions of arbitrary order for any random variable in a statistical dynamical system can be calculated as higher-order response functions of the mean history of the variable. The response is to a ``control…

chao-dyn · Physics 2009-10-31 Gregory L. Eyink

The Schwinger-Keldysh diagram technique is usually involved in the calculation of real-time in-in correlation functions. In the case of a thermal state, one can analytically continue imaginary-time Matsubara correlation functions to real…

High Energy Physics - Theory · Physics 2022-12-09 Nikita Kolganov

To fully capitalize on the potential and versatility of resonant inelastic x-ray scattering (RIXS), it is essential to develop the capability to interpret different RIXS contributions through calculations, including the dependence on…

We introduce history-dependent discrete-time quantum random walk models by adding uncorrelated memory terms and also by modifying Hamiltonian of the walker to include couplings with memory-keeping agents. We next numerically study the…

Quantum Physics · Physics 2009-07-10 J. B. Stang , A. T. Rezakhani , B. C. Sanders

We propose a relaxation time approximation for the description of the dynamics of strongly excited fermion systems. Our approach is based on time-dependent density functional theory at the level of the local density approximation. This…

Atomic and Molecular Clusters · Physics 2016-01-26 P. -G. Reinhard , E. Suraud

How a closed interacting quantum many-body system relaxes and dephases as a function of time is a fundamental question in thermodynamic and statistical physics. In this work, we analyse and observe the persistent temporal fluctuations after…

Statistical Mechanics · Physics 2020-09-22 Harvey B. Kaplan , Lingzhen Guo , Wen Lin Tan , Arinjoy De , Florian Marquardt , Guido Pagano , Christopher Monroe

In this paper, we consider the long time asymptotics of multi-time correlation functions for quantum dynamical systems that are sufficiently random to relax to a ``reference state''. In particular, the evolution of such systems must have a…

Quantum Physics · Physics 2007-05-23 J. Andries , F. Benatti , M. De Cock , M. Fannes

The equations of time-dependent density functional theory are derived, via the expression for the quantum weak value, from ring polymer quantum theory using a symmetry between time and imaginary time. The imaginary time path integral…

Quantum Physics · Physics 2025-03-21 Russell B. Thompson , Zarin Tasneem , Yves Caudano

While seemingly straightforward in principle, the reliable estimation of rate constants is seldom easy in practice. Numerous issues, such as the complication of poor reaction coordinates, cause obvious approaches to yield unreliable…

The relative timing of action potentials in neurons recorded from local cortical networks often shows a non-trivial dependence, which is then quantified by cross-correlation functions. Theoretical models emphasize that such spike train…

Neurons and Cognition · Quantitative Biology 2017-06-28 Taskin Deniz , Stefan Rotter

An explicit expression for the quadratic density-response function of a many-electron system is obtained in the framework of the time-dependent density-functional theory, in terms of the linear and quadratic density-response functions of…

Materials Science · Physics 2009-11-10 V. U. Nazarov , J. M. Pitarke , C. S. Kim , Y. Takada

Time domain interferometry is a promising method to characterizes spatial and temporal correlations at x-ray energies, via the so-called intermediate scattering function and the related dynamical couple correlations. However, so far, it has…

Quantum Physics · Physics 2019-01-23 Salvatore Castrignano , Jörg Evers

We investigate quantum correlations in time in different approaches. We assume that temporal correlations should be treated in an even-handed manner with spatial correlations. We compare the pseudo-density matrix formalism with several…

Quantum Physics · Physics 2020-12-23 Tian Zhang , Oscar Dahlsten , Vlatko Vedral

Modern X-ray spectroscopy has proven itself as a robust tool for probing the electronic structure of atoms in complex environments. Despite working on energy scales that are much larger than those corresponding to nuclear motions, taking…

Chemical Physics · Physics 2017-06-28 Sven Karsten , Sergey I. Bokarev , Saadullah G. Aziz , Sergei D. Ivanov , Oliver Kühn

The quantum regression theorem states that the correlations of a system at two different times are governed by the same equations of motion as the temporal response of the average values. Such a relation provides a powerful framework for…