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Related papers: Spectral ageing: a new age perspective

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In solar physics, especially in exploratory stages of research, it is often necessary to compare the power spectra of two or more time series. One may, for instance, wish to estimate what the power spectrum of the combined data sets might…

Astrophysics · Physics 2008-12-18 P. A. Sturrock , J. D. Scargle , G. Walther , M. S. Wheatland

The focus on managing problems that can arise for older adults has meant that extant HCI and Ageing research has not given the concepts of 'age' and 'ageing' the explicit theoretical attention they deserve. Attending to this gap, we…

Living systems are subject to the arrow of time; from birth, they undergo complex transformations (self-organization) in a constant battle for survival, but inevitably ageing and disease trap them to death. Can ageing be understood and…

Other Quantitative Biology · Quantitative Biology 2020-08-21 Tamàs Fülöp , Mathieu Desroches , Fernando Antônio Nóbrega Santos , Serafim Rodrigues

The spectral form factor is a dynamical probe for level statistics of quantum systems. The early-time behaviour is commonly interpreted as a characterization of two-point correlations at large separation. We argue that this interpretation…

Disordered Systems and Neural Networks · Physics 2025-10-07 Wouter Buijsman , Vadim Cheianov , Vladimir Gritsev

We present three new methods for determining the age of groups of pre-main-sequence stars. The first, creating empirical isochrones allows us to create a robust age ordering, but not to derive actual ages. The second, using the width of the…

Solar and Stellar Astrophysics · Physics 2009-09-10 Tim Naylor , N. J. Mayne , R. D. Jeffries , S. P. Littlefair , Eric S. Saunders

The wavelength calibration of spectrographs is an essential but challenging task in many disciplines. Calibration is traditionally accomplished by imaging the spectrum of a light source containing features that are known to appear at…

Instrumentation and Methods for Astrophysics · Physics 2018-04-04 Neil Thomas

The rotation rate, level of magnetic activity and surface lithium abundance are age-dependent quantities in stars of about a solar mass and below. The physical reasons for the evolution of these phenomena are qualitatively understood, but…

Solar and Stellar Astrophysics · Physics 2015-06-19 R. D. Jeffries

We show that the UV flux of old stellar systems can tell us about their ages. Two independent populations synthesis groups that have had wildly different views have here worked together and generated two solutions that can be easily tested…

Astrophysics · Physics 2009-09-28 Yi , Lee , Woo , Demarque , Oemler

We propose a new observable for the 21cm global signal during the dark ages, the dark-age consistency ratio, which is motivated from the fact that the shape of the functional form of the brightness temperature against the frequency is…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-14 Fumiya Okamatsu , Teppie Minoda , Tomo Takahashi , Daisuke Yamauchi , Shintaro Yoshiura

In this third paper of a series on the precision of obtaining ages of stellar populations using the full spectrum fitting technique, we examine the precision of this technique in deriving possible age spreads within a star cluster. We test…

Astrophysics of Galaxies · Physics 2021-05-12 Randa Asa'd , Paul Goudfrooij , A. M. As'ad , H. G. El-Mir , L. Begum , A. Aljasmi , O. Almatroushi

Determining the sequence of events in the formation of stars and planetary systems and their time-scales is essential for understanding those processes, yet establishing ages is fundamentally difficult because we lack direct indicators. In…

Solar and Stellar Astrophysics · Physics 2015-06-18 David R. Soderblom , Lynne A. Hillenbrand , Rob D. Jeffries , Eric E. Mamajek , Tim Naylor

Machine-learning-based age estimation has received lots of attention. Traditional age estimation mechanism focuses estimation age error, but ignores that there is a deviation between the estimated age and real age due to disease.…

Computer Vision and Pattern Recognition · Computer Science 2021-03-12 Fan Li , Yongming Li , Pin Wang , Jie Xiao , Fang Yan , Xinke Li

This paper investigates the problem of estimating the spectral power parameters of random analog sources using numerical measurements acquired with minimum digitization complexity. Therefore, spectral analysis has to be performed with…

Signal Processing · Electrical Eng. & Systems 2019-10-29 Manuel S. Stein

A new method to calculate the spectrum using cascaded open systems and master equations is presented. The method uses two state analyzer atoms which are coupled to the system of interest, whose spectrum of radiation is read from the…

Quantum Physics · Physics 2015-06-26 Martti Havukainen , Stig Stenholm

The status of the solar neutrino problem is reviewed. Attempts to explain the observed deficit and spectral distortion, both by astrophysical and particle physics methods, are described. It is argued that the comparison of all experiments…

High Energy Physics - Phenomenology · Physics 2011-06-02 Paul Langacker

The sum-energy spectrum of electrons emitted in double-beta decay is a well-known diagnostic for the nature of the physics which is responsible for the decay. Three types of spectra are usually considered when these experiments are…

High Energy Physics - Phenomenology · Physics 2007-05-23 C. P. Burgess

We present some simple computer simulations that indicate that at short time aging is realized in a simple model of binary glasses. It is interesting to note that modest computer simulations are enough to evidenziate this effect. We also…

Disordered Systems and Neural Networks · Physics 2008-02-03 Giorgio Parisi

This note is to indicate the new sphere of applicability of the method developed by Mlak as well as by the author. Restoring those ideas is summoned by current developments concerning $K$-spectral sets on numerical ranges.

Functional Analysis · Mathematics 2009-03-20 F. H. Szafraniec

Equations arising in General Relativity are usually too complicated to be solved analytically and one has to rely on numerical methods to solve sets of coupled partial differential equations. Among the possible choices, this paper focuses…

General Relativity and Quantum Cosmology · Physics 2016-06-22 Philippe Grandclement , Jérôme Novak

The efficient use of near-IR data in studies of external stellar populations depends on our ability to recognize the nature of the predominant sources of light, and to interprete these findings in terms of age and metallicity. Here we focus…

Astrophysics · Physics 2007-05-23 A. Lancon , M. Mouhcine
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