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Related papers: A $Z_1^2$ framework for rotational-parameter estim…

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This research leverages Conformal Prediction (CP) in the form of Conformal Predictive Systems (CPS) to accurately estimate uncertainty in a suite of machine learning (ML)-based radio metric models [1] as well as in a 2-D map-based ML path…

Machine Learning · Computer Science 2025-01-14 Alexis Bose , Jonathan Ethier , Ryan G. Dempsey , Yifeng Qiu

We investigate the cross-correlation between astrometric and timing-residual observables for distant sources, such as pulsars and galaxies, and equivalent observables for nearby solar system bodies. Using the unified spin-weighted formalism…

General Relativity and Quantum Cosmology · Physics 2025-10-31 Elias Fink , Carlo Contaldi , Giorgio Mentasti

Frequency metrology outperforms any other branch of metrology in accuracy (parts in $10^{-16}$) and small fluctuations ($<10^{-17}$). In turn, among celestial bodies, the rotation speed of millisecond pulsars (MSP) is by far the most stable…

Data Analysis, Statistics and Probability · Physics 2022-02-04 Siyuan Chen , Francois Vernotte , Enrico Rubiola

Be/X-ray binary pulsars show transient outbursts and complex timing behaviour, including millihertz quasi-periodic oscillations (QPOs), whose physical origin and energy dependence remain poorly understood. We aim to characterise the…

High Energy Astrophysical Phenomena · Physics 2026-05-06 Zihan Yang , Ruican Ma , Mariano Méndez , Z. X. Li , Q. C. Zhao , Panping Li , Lian Tao , Shuang-Nan Zhang , Liang Zhang , Hua Feng , Xiang Ma , Yue Huang

We have detected quasi-periodic oscillations (QPOs) near 1 kHz from the low mass X-ray binary 4U 0614+091 in observations with XTE. The observations span several months and sample the source over a large range of X-ray luminosity. In every…

Astrophysics · Physics 2009-10-28 E. Ford , P. Kaaret , M. Tavani , D. Barret , P. Bloser , J. Grindlay , B. A. Harmon , W. S. Paciesas , S. N. Zhang

Pulsar timing array projects measure the pulse arrival times of millisecond pulsars for the primary purpose of detecting nanohertz-frequency gravitational waves. The measurements include contributions from a number of astrophysical and…

We present phase-connected timing ephemerides, polarization pulse profiles and Faraday rotation measurements of 12 pulsars discovered by the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in the Commensal Radio Astronomy FAST…

One of the most promising targets for Pulsar Timing Arrays (PTAs) is identifying an individual supermassive black hole binary (SMBHB) out of the population of binaries theorized to produce a gravitational wave background (GWB). In this…

Instrumentation and Methods for Astrophysics · Physics 2026-04-21 Levi Schult , Polina Petrov , Stephen R. Taylor , Nihan Pol , Nima Laal , Maria Charisi , Chung-Pei Ma

Many Galactic black hole and neutron star sources in low X-ray mass binaries show QPOs (quasi periodic oscillations) in their observed X-ray fluxes, i.e. peaks in the Fourier variability power spectra. Pairs of twin peaks are observed, and…

Astrophysics · Physics 2007-05-23 Marek A. Abramowicz , Wlodek Kluzniak , Zdenek Stuchlik , Gabriel Torok

We examine the accuracy of estimation of parameters of the gravitational-wave signals from spinning neutron stars that can be achieved from observations by Earth-based laser interferometers. We consider a model of the signal consisting of…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Piotr Jaranowski , Andrzej Królak

High frequency quasi-periodic oscillations (QPOs) from weakly magnetized neutron stars display rapid frequency variability and high coherence with quality factors up to at least 200 at frequencies around 850 Hz. Their parameters have been…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Didier Barret , Simon Vaughan

The Cadmium Zinc Telluride Imager (CZTI) onboard AstroSat, an open detector above $\sim$100 keV, is a promising tool for the investigation of hard X-ray characteristics of $\gamma$-ray pulsars. A custom algorithm has been developed to…

High Energy Astrophysical Phenomena · Physics 2022-12-14 K. G. Anusree , Dipankar Bhattacharya , Varun Bhalerao , Akash Anumarlapudi

We present high-precision timing of five millisecond pulsars (MSPs) carried out for more than seven years; four pulsars are in binary systems and one is isolated. We are able to measure the pulsars' proper motions and derive an estimate for…

The major programme for observing young, non-recycled pulsars with the Parkes telescope has transitioned from a narrow-band system to an ultra-wideband system capable of observing between 704 and 4032 MHz. We report here on the initial two…

High Energy Astrophysical Phenomena · Physics 2021-02-10 Simon Johnston , C. Sobey , S. Dai , M. Keith , M. Kerr , R. N. Manchester , L. S. Oswald , A. Parthasarathy , R. M. Shannon , P. Weltevrede

In this paper, two types of linear estimators are considered for three related estimation problems involving set-theoretic uncertainty pertaining to $\mathcal{H}_{2}$ and $\mathcal{H}_{\infty}$ balls of frequency-responses. The problems at…

Systems and Control · Electrical Eng. & Systems 2022-01-11 Gilberto O. Corrêa , Marlon M. López-Flores

Continuous gravitational waves, i.e., persistent and nearly-monochromatic signals emitted by asymmetric spinning neutron stars, remain elusive. Searches for these signals from unknown binary systems are the most computationally challenging,…

General Relativity and Quantum Cosmology · Physics 2026-05-19 P. B. Covas , M. A. Papa , R. Prix

Observing and timing a group of millisecond pulsars (MSPs) with high rotational stability enables the direct detection of gravitational waves (GWs). The GW signals can be identified from the spatial correlations encoded in the…

Intensity mapping experiments will soon have surveyed large swathes of the sky, providing information about the underlying matter distribution of the early universe. The resulting maps can be used to recover statistical information, such as…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-15 Lisa McBride , Adrian Liu

The highly stable spin of neutron stars can be exploited for a variety of (astro-)physical investigations. In particular arrays of pulsars with rotational periods of the order of milliseconds can be used to detect correlated signals such as…

We report on an experimental investigation of the transition of a quantum system with integrable classical dynamics to one with violated time-reversal (T) invariance and chaotic classical counterpart. High-precision experiments are…

Quantum Physics · Physics 2024-01-30 Xiaodong Zhang , Weihua Zhang , Jiongning Che , Barbara Dietz