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We present a method of selecting quasars up to redshift $\approx$ 6 with random forests, a supervised machine learning method, applied to Pan-STARRS1 and WISE data. We find that, thanks to the increasing set of known quasars we can assemble…

We apply a state-of-the-art transformer algorithm to 221 deg$^2$ of the Kilo Degree Survey (KiDS) to search for new strong gravitational lenses (SGL). We test four transformer encoders trained on simulated data from the Strong Lens Finding…

We apply instance-based machine learning in the form of a k-nearest neighbor algorithm to the task of estimating photometric redshifts for 55,746 objects spectroscopically classified as quasars in the Fifth Data Release of the Sloan Digital…

We study the prospects of characterising Dark Matter at colliders using Machine Learning (ML) techniques. We focus on the monojet and missing transverse energy (MET) channel and propose a set of benchmark models for the study: a typical…

High Energy Physics - Phenomenology · Physics 2021-06-23 C. K. Khosa , V. Sanz , M. Soughton

We present a new measurement of the space density of high redshift (3.0<z<4.5), X-ray selected QSOs obtained by exploiting the deep and uniform multiwavelength coverage of the COSMOS survey. We have assembled a statistically large (40…

In the near future, new surveys promise a significant increase in the number of quasars (QSO) at large redshifts. This will help to constrain the dark energy models using quasars. The Large Synoptic Survey Telescope (LSST) will cover over…

Astrophysics of Galaxies · Physics 2019-10-08 Mary Loli Martínez-Aldama , Swayamtrupta Panda , Bożena Czerny , Michal Zajaček

The validity screen (Cacioli, 2026d, 2026e) classifies LLM confidence signals as Valid, Indeterminate, or Invalid. We test whether these classifications predict selective prediction performance. Twenty frontier LLMs from seven families were…

Computation and Language · Computer Science 2026-04-21 Jon-Paul Cacioli

Strong lensed quasi-stellar objects (QSOs) are valuable probes of the universe in numerous aspects. Two of these applications, reverberation mapping and measuring time delays for determining cosmological parameters, require the source QSOs…

Astrophysics of Galaxies · Physics 2023-08-02 Yoon Chan Taak , Tommaso Treu

Variable stars with well-calibrated period-luminosity relationships provide accurate distance measurements to nearby galaxies and are therefore a vital tool for cosmology and astrophysics. While these measurements typically rely on samples…

Instrumentation and Methods for Astrophysics · Physics 2019-04-09 Markus Michael Rau , Sergey E. Koposov , Hy Trac , Rachel Mandelbaum

In this work, we test whether gradient-boosting algorithms, trained on broadband photometric data from traditional Lyman-$\alpha$ emitting (LAE) surveys, can efficiently and accurately identify LAE candidates from typical star-forming…

Astrophysics of Galaxies · Physics 2025-09-30 A. Vale , A. Paulino-Afonso , A. Humphrey , P. A. C. Cunha , B. Ribeiro , B. Cerqueira , R. Carvajal , J. Fonseca

Diabetes is a major health problem in both developing and developed countries and its incidence is rising dramatically. In this study, we investigate a novel automatic approach to diagnose Diabetes disease based on Feature Weighted Support…

Machine Learning · Computer Science 2012-01-12 Davar Giveki , Hamid Salimi , GholamReza Bahmanyar , Younes Khademian

We present the X-ray pipeline developed for the purpose of the cluster search in the XMM-LSS survey. It is based on a two-stage procedure via a dedicated handling of the Poisson nature of the signal: (1) source detection on multi-resolution…

We present spectroscopy of individual stars in 26 Magellanic Cloud (MC) star clusters with the aim of estimating dynamical masses and $V$-band mass-to-light ($M/L_V$) ratios over a wide range in age and metallicity. We obtained 3137…

Quantum kernel methods have been proposed as a promising approach for leveraging near-term quantum computers for supervised learning, yet rigorous benchmarks against strong classical baselines remain scarce. We present a comprehensive…

Quantum Physics · Physics 2026-04-22 Siavash Kakavand , Christoph Strohmeyer , Michael Schlotter

The non-linear relationship between the monochromatic X-ray and UV luminosities in quasars offers the possibility of using high-z quasars as standard candles for cosmological testing. In this paper, we use a high-quality catalog of 1598…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-17 Liuyuan Fan , Guanwen Fang , Jian Hu

Diagnosis results are highly dependent on the volume of test set. To derive the most efficient test set, we propose several machine learning based methods to predict the minimum amount of test data that produces relatively accurate…

Machine Learning · Computer Science 2020-10-30 Kaiming Fu , Yulu Jin , Zhousheng Chen

In this work we train three decision-tree based ensemble machine learning algorithms (Random Forest Classifier, Adaptive Boosting and Gradient Boosting Decision Tree respectively) to study quasar selection in the variable source catalog in…

Astrophysics of Galaxies · Physics 2021-06-02 Da-Ming Yang , Zhang-Liang Xie , Jun-Xian Wang

We present 100 multiple cluster candidates selected from the OGLE catalog of star clusters in the Large Magellanic Cloud. Statistical analysis shows that the significant fraction of these objects may constitute physical systems. Coeval ages…

Astrophysics · Physics 2007-05-23 G. Pietrzynski , A. Udalski

We present a comparison of X-ray and optical luminosities and luminosity functions of cluster candidates from a joint optical/X-ray survey, the ROSAT Optical X-Ray Survey. Completely independent X-ray and optical catalogs of 23 ROSAT fields…

The last comprehensive catalogue of high-mass X-ray binaries in the Small Magellanic Cloud (SMC) was published about ten years ago. Since then new such systems were discovered, mainly by X-ray observations with Chandra and XMM-Newton. For…

Astrophysics of Galaxies · Physics 2016-02-03 Frank Haberl , Richard Sturm