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A modified version of the folded aplanatic Gregory telescope equipped with a spherical two-lens corrector is proposed for observations requiring a high signal-to-noise ratio. The basic telescope model has an aperture of 400 mm (f/3.0), its…

Instrumentation and Methods for Astrophysics · Physics 2017-12-06 V. Yu. Terebizh

Integrated superconducting spectrometers (ISSs) for wideband sub-mm astronomy utilise quasi-optical systems for coupling radiation from the telescope to the instrument. Misalignment in these systems is detrimental to the system performance.…

Instrumentation and Methods for Astrophysics · Physics 2024-04-24 A. Moerman , K. Karatsu , S. J. C. Yates , R. Huiting , F. Steenvoorde , S. O. Dabironezare , T. Takekoshi , J. J. A. Baselmans , B. R. Brandl , A. Endo

Weak lensing by large scale structure induces correlated ellipticities in the images of distant galaxies. The two-point correlation is determined by the matter power spectrum along the line of sight. We use the fully nonlinear evolution of…

Astrophysics · Physics 2009-10-28 Bhuvnesh Jain , Uros Seljak

Weak gravitational lensing is normally assumed to have only two principle effects: a magnification of a source and a distortion of the sources shape in the form of a shear. However, further distortions are actually present owing to changes…

General Relativity and Quantum Cosmology · Physics 2015-12-02 Chris Clarkson

Quantum anomalies are the breaking of a classical symmetry by quantum fluctuations. They dictate how physical systems of diverse nature, ranging from fundamental particles to crystalline materials, respond topologically to external…

Mesoscale and Nanoscale Physics · Physics 2016-02-12 Jan Behrends , Adolfo G. Grushin , Teemu Ojanen , Jens H. Bardarson

Planar chiral structures possess a two dimensional handedness that is associated with broken mirror symmetry. Such motifs span vast length scales; examples include certain pinwheel molecules, nautilus shells, cyclone wind patterns and…

Weak lensing experiments are a powerful probe of cosmology through their measurement of the mass distribution of the universe. A challenge for this technique is to control systematic errors that occur when measuring the shapes of distant…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Alexandre Refregier , Tomasz Kacprzak , Adam Amara , Sarah Bridle , Barnaby Rowe

Weak lensing is the distortion (polarization) of images of distant objects, such as high redshift galaxies, by gravitational fields in the limit where the distortion is small. Gravitational potential fluctuations due to large scale…

Astrophysics · Physics 2015-06-24 Jens Verner Villumsen

This article offers a study of the Calder\'on type inverse problem of determining up to second order coefficients of the higher order elliptic operator. Here we show that it is possible to determine an anisotropic second order perturbation…

Analysis of PDEs · Mathematics 2021-09-21 Sombuddha Bhattacharyya , Tuhin Ghosh

The standard description of cosmological observables is incomplete, because it does not take into account the correct angular parametrization of the sky, i.e. the one determined by the observer frame. The corresponding corrections must be…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-02 Ermis Mitsou , Jaiyul Yoo

This paper investigates the effects that perturbations to an optical system, such as translations or rotations of the optical elements, have on the final location where a light ray strikes a detector. Symmetry arguments are employed to give…

Physics Education · Physics 2007-05-23 Jason H. Steffen

Future NASA X-ray Observatories will shed light on a variety of high-energy astrophysical phenomena. Off-plane reflection gratings can be used to provide high throughput and spectral resolution in the 0.3--1.5 keV band, allowing for…

Instrumentation and Methods for Astrophysics · Physics 2015-06-17 Ryan Allured , Randall L. McEntaffer

We have undertaken a Near-IR Weak Lensing (NIRWL) analysis of the wide-field CANDELS HST/WFC3-IR F160W observations. With the Gaia proper-motion-corrected catalog as an astrometric reference, we updated the astrometry of the five CANDELS…

Telescopes with unobstructed pupil are known to deliver clean point spread function (PSF) to their focal plane, in contrast to traditional telescopes with obstructed pupil. Recent progress in the manufacturing aspheric surfaces and mounting…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 Balasubramanian Singaravelu , Remi A. Cabanac

We present a three dimensional cosmic shear analysis of the Hubble Space Telescope COSMOS survey, the largest ever optical imaging program performed in space. We have measured the shapes of galaxies for the tell-tale distortions caused by…

We give a complete geometric description of conformal anomalies in arbitrary, (necessarily even) dimension. They fall into two distinct classes: the first, based on Weyl invariants that vanish at integer dimensions, arises from finite --…

High Energy Physics - Theory · Physics 2008-11-26 S. Deser , A. Schwimmer

In the present paper we consider quantitative estimation of the tolerances widening in optical systems with curved detectors. The gain in image quality allows to loosen the margins for manufacturing and assembling errors. On another hand,…

In this paper, we introduce a system based on transfer learning for detecting segment misalignment in multimirror satellites, such as future CubeSat designs and the James Webb Space Telescope (JWST), using image-based methods. When a mirror…

Computer Vision and Pattern Recognition · Computer Science 2024-07-31 C. Tanner Fredieu , Jonathan Tesch , Andrew Kee , David Redding

Cubesats present unique opportunities for observational astronomy in the modern era. They are useful in observing difficult-to-access wavelength regions and long-term monitoring of interesting astronomical sources. However, conventional…

Instrumentation and Methods for Astrophysics · Physics 2025-07-14 Anwesh Kumar Mishra , Gourav Banerjee , Rekhesh Mohan , Maheswar Gopinathan

The joint design of the optical system and the downstream algorithm is a challenging and promising task. Due to the demand for balancing the global optimal of imaging systems and the computational cost of physical simulation, existing…

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