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Attempts to measure the variability of the fine structure constant alpha over cosmological time, using spectra of high redshift quasars have produced conflicting results. We use the Many Multiplet (MM) method with Mg II and Fe II lines on…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 A. Songaila , L. L. Cowie

Microvariability consists in small time scale variations of low amplitude in the photometric light curves of quasars, and represents an important tool to investigate their inner core. Detection of quasar microvariations is challenging for…

Instrumentation and Methods for Astrophysics · Physics 2016-08-08 J. A. de Diego , J. Polednikova , A. Bongiovanni , A. M. Pérez García , M. A. De Leo , T. Verdugo , J. Cepa

Quantum parameter estimation is central to many fields such as quantum computation, communications and metrology. Optimal estimation theory has been instrumental in achieving the best accuracy in quantum parameter estimation, which is…

Quantum Physics · Physics 2015-06-18 Shibdas Roy , Ian R. Petersen , Elanor H. Huntington

We describe a scalable stochastic method for the experimental measurement of generalized fidelities characterizing the accuracy of the implementation of a coherent quantum transformation. The method is based on the motion reversal of random…

Quantum Physics · Physics 2009-11-11 Joseph Emerson , Robert Alicki , Karol Zyczkowski

Hyperspectral pansharpening has received much attention in recent years due to technological and methodological advances that open the door to new application scenarios. However, research on this topic is only now gaining momentum. The most…

Computer Vision and Pattern Recognition · Computer Science 2025-07-16 Giuseppe Guarino , Matteo Ciotola , Gemine Vivone , Giovanni Poggi , Giuseppe Scarpa

Direct imaging of exoplanets requires very high contrast levels, which are obtained using coronagraphs. But residual quasi-static aberrations create speckles in the focal plane downstream of the coronagraph which mask the planet. This…

Instrumentation and Methods for Astrophysics · Physics 2015-06-16 J. Mazoyer , P. Baudoz , R. Galicher , M. Mas , G. Rousset

Uncertainty quantification based on generalized polynomial chaos has been used in many applications. It has also achieved great success in variation-aware design automation. However, almost all existing techniques assume that the parameters…

Numerical Analysis · Mathematics 2019-06-21 Chunfeng Cui , Zheng Zhang

Recently, GRAVITY onboard the Very Large Telescope Interferometer (VLTI) first spatially resolved the structure of the quasar 3C 273 with an unprecedented resolution of $\sim 10\mu$as. A new method of measuring parallax distances has been…

Astrophysics of Galaxies · Physics 2021-04-21 Yu-Yang Songsheng , Yan-Rong Li , Pu Du , Jian-Min Wang

Quantum computing holds potential for accelerating the simulation of fluid dynamics. However, hardware noise in the noisy intermediate-scale quantum era significantly distorts simulation accuracy. Although error magnitudes are frequently…

Quantum Physics · Physics 2025-12-30 Jiahua Yang , Zhen Lu , Yue Yang

The accuracies of modern quantum logic clocks have surpassed those of standard atomic fountain clocks. These clocks also provide a greater degree of control, because before and after clock queries, we are able to apply chosen unitary…

Quantum Physics · Physics 2011-07-28 Michael Mullan , Emanuel Knill

Reconstructive spectrometers are a promising emerging class of devices that combine complex light scattering with inference to enable compact, high-resolution spectrometry. Thus far, the physical determinants of these devices' performance…

Optics · Physics 2026-03-24 Changyan Zhu , Hsuan Lo , Jianbo Yu , Qijie Wang , Y. D. Chong

The time domain is the emerging forefront of astronomical research with new facilities and instruments providing unprecedented amounts of data on the temporal behavior of astrophysical populations. Dealing with the size and complexity of…

Astrophysics of Galaxies · Physics 2017-06-14 Matthew J. Graham , S. G. Djorgovski , Daniel J. Stern , Andrew J. Drake , Ashish Mahabal

Recent attempts to constrain cosmological variation in the fine structure constant, alpha, using quasar absorption lines have yielded two statistical samples which initially appear to be inconsistent. One of these samples was subsequently…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-16 Julian A. King , Daniel J. Mortlock , John K. Webb , Michael T. Murphy

Quantum measurements are not deterministic. For this reason quantum measurements are repeated for a number of shots on identically prepared systems. The uncertainty in each measurement depends on the number of shots and the expected outcome…

Quantum Physics · Physics 2025-03-12 Pieter Thijs Eendebak

Determination of the fine structure constant alpha and search for its possible variation are considered. We focus on a role of the fine structure constant in modern physics and discuss precision tests of quantum electrodynamics. Different…

Atomic Physics · Physics 2015-06-26 Savely G. Karshenboim

Measurement incompatibility is a cornerstone of quantum mechanics. In the context of estimating multiple parameters of a quantum system, this manifests as a fundamental trade-off between the precisions with which different parameters can be…

Quantum Physics · Physics 2025-11-11 Simon K. Yung , Aritra Das , Jun Suzuki , Ping Koy Lam , Jie Zhao , Lorcán O. Conlon , Syed M. Assad

Cosmology contributes a good deal to the investigation of variation of fundamental physical constants. High resolution data is available and allows for detailed analysis over cosmological distances and a multitude of methods were developed.…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-28 M. Wendt , D. Reimers , P. Molaro

The ability to resolve detail in the object that is being imaged, named by resolution, is the core parameter of an imaging system. Super-resolution is a class of techniques that can enhance the resolution of an imaging system and even…

Data Structures and Algorithms · Computer Science 2022-10-13 Yaonan Jin , Daogao Liu , Zhao Song

Under ideal conditions, quantum metrology promises a precision gain over classical techniques scaling quadratically with the number of probe particles. At the same time, no-go results have shown that generic, uncorrelated noise limits the…

Quantum Physics · Physics 2017-07-13 J. B. Brask , R. Chaves , J. Kolodynski

We statistically analyse a recent sample of data points measuring the fine-structure constant alpha (relative to the terrestrial value) in quasar absorption systems. Using different statistical techniques, we find general agreement with…

Cosmology and Nongalactic Astrophysics · Physics 2012-08-02 J. C. Berengut , E. M. Kava , V. V. Flambaum