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We compare galaxy number counts in HST/ACS fields containing moderate-redshift (0.2<z<1.0) strong gravitational lenses with those in two control samples: (1) the first square degree of the COSMOS survey, comprising 259 ACS fields and (2) 20…

Cosmology and Nongalactic Astrophysics · Physics 2011-04-07 C. D. Fassnacht , L. V. E. Koopmans , K. C. Wong

We study mirror symmetry (A-side vs B-side) in the framework of quantum differential systems. We focuse on the logarithmic and non-resonant case, which describes the geometric situation. We show that quantum differential systems provide a…

Algebraic Geometry · Mathematics 2015-02-03 Antoine Douai

Targeting at the realization of scalable photonic quantum technologies, the generation of many photons, their propagation in large optical networks, and a subsequent detection and analysis of sophisticated quantum correlations are essential…

We report the discovery, spectroscopic confirmation, and mass modelling of the gravitationally lensed quasar system PS J0630-1201. The lens was discovered by matching a photometric quasar catalogue compiled from Pan-STARRS and WISE…

Concave mirrors are fundamental optical elements, yet some easily observed behaviors are rarely addressed in standard textbooks, such as the formation of multiple reflected images. Here we investigate self-imaging -- where the observer is…

Optics · Physics 2025-12-30 Thach A. Nguyen , Kaitlyn S. Yasumura , Duy V. Tran , Trung V. Phan

The goal of supervised feature selection is to find a subset of input features that are responsible for predicting output values. The least absolute shrinkage and selection operator (Lasso) allows computationally efficient feature selection…

Machine Learning · Statistics 2019-01-07 Makoto Yamada , Wittawat Jitkrittum , Leonid Sigal , Eric P. Xing , Masashi Sugiyama

Time-varying optical materials have attracted recent interest for their potential to enable frequency conversion, nonreciprocal physics, photonic time-crystals, and more. However, the description of time-varying materials has been primarily…

Singularities of caustics appeared in gravitational lensing effect are discussed analytically. Multipole expansion model of lensing object is mainly studied since it is tractable and universal. Our analyses are confirmed by numerical…

Astrophysics · Physics 2009-10-28 Y. Kakigi , T. Okamura , T. Fukuyama

Quantum entanglement reflects itself through non-local correlations among the subsystems of a quantum system. This thesis focuses on constructing a complete set of local invariants characterizing symmetric two qubit systems and analyzing…

Quantum Physics · Physics 2009-07-14 M. S. Uma

The distribution of dark and luminous matter can be mapped around galaxies that gravitationally lens background objects into arcs or Einstein rings. New surveys will soon observe hundreds of thousands of galaxy lenses, and current,…

We study a class of gravitational lensing systems consisting of an inclined ring/belt, with and without an added point mass at the centre. We show that a common feature of such systems are so-called "pseudo-caustics", across which the…

Earth and Planetary Astrophysics · Physics 2016-12-21 Ethan Lake , Zheng Zheng

We consider the possible gain in the measurement of lensing shear from imaging data in multiple filters. Galaxy shapes may differ significantly across filters, so that the same galaxy offers multiple samples of the shear. On the other…

Astrophysics · Physics 2008-11-26 Mike Jarvis , Bhuvnesh Jain

In gravitational lensing, central images in quads can serve as a powerful probe of the inner regions of lens galaxies. The presence of an offset central supermassive black hole (SMBH) has the potential to distort the time-delay surface in a…

Astrophysics of Galaxies · Physics 2023-04-26 Derek Perera , Liliya L. R. Williams , Claudia Scarlata

Real astrophysical lenses typically lack axisymmetry, necessitating the study of gravitational-wave (GW) lensing by elliptical mass distributions to accurately assess detectability and waveform interpretation. We investigate strong lensing…

General Relativity and Quantum Cosmology · Physics 2025-07-08 Saif Ali , Michael Kesden , Lindsay King

The observables in a strong gravitational lens are usually just the image positions and sometimes the flux ratios. We develop a new and simple algorithm which allows a set of models to be fitted exactly to the observations. Taking our cue…

Astrophysics · Physics 2008-11-26 N. W. Evans , H. J. Witt

Gravitational lensing of a background source by a foreground galaxy lens occasionally produces four images of the source. The cusp and the fold relations impose conditions on the ratios of magnifications of these four-image lenses. In this…

Astrophysics · Physics 2009-11-11 Amir Babak Aazami , Priyamvada Natarajan

Identifying multiply imaged quasars is challenging due to their low density in the sky and the limited angular resolution of wide field surveys. We show that multiply imaged quasars can be identified using unresolved light curves, without…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-11 Satadru Bag , Arman Shafieloo , Kai Liao , Tommaso Treu

When traveling from their source to the observer, gravitational waves can get deflected by massive objects along their travel path. When the lens is massive enough and the source aligns closely with the line-of-sight to the lens, the wave…

General Relativity and Quantum Cosmology · Physics 2022-12-28 Justin Janquart , Anupreeta More , Chris Van Den Broeck

Gravitationally lensed Type Ia supernovae are an emerging probe with great potential for constraining dark energy, spatial curvature, and the Hubble constant. The multiple images and their time delayed and magnified fluxes may be…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-25 Mikhail Denissenya , Satadru Bag , Alex G. Kim , Eric V. Linder , Arman Shafieloo

Gravitational time delays offer unique, independent measurements of the Hubble constant, $H_0$. Precise measurements of $H_0$ stand as one of the most pressing challenges in modern cosmology, and to do so with time delays requires precise…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-19 D. M. Williams , T. Treu , S. Birrer , A. J. Shajib , K. C. Wong , T. Morishita , T. Schmidt , M. Stiavelli