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Related papers: Gravitational Microlensing by Rotating Stars

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The formation of compact objects like stars and black holes is strongly constrained by the requirement that nearly all of the initial angular momentum of the diffuse material from which they form must be removed or redistributed during the…

Solar and Stellar Astrophysics · Physics 2010-01-06 Richard B. Larson

A detailed analysis is presented of gravitational microlensing by intervening compact objects of the black hole shadows imaged by the Event Horizon Telescope (EHT). We show how the center, size, and shape of the shadow depend on the…

Astrophysics of Galaxies · Physics 2024-05-14 Himanshu Verma , Joseph Silk

A circularly polarized rotationally symmetric paraxial laser beams carries hbar angular momentum per photon as spin. Focussing the beam with a rotationally symmetric lens cannot change this angular momentum flux, yet the focussed beam must…

Gravitational lensing of gravitational waves provides a potential new probe of dark matter structures. In this work, we consider the microlensing effect on gravitational wave signals from black hole binaries induced by low-mass dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-14 Malcolm Fairbairn , Juan Urrutia , Ville Vaskonen

The standard treatment of gravitational lensing by a point mass lens M is based on a weak-field deflection angle a = 2/x, where x = (r c^2)/(2 G M) with r the distance of closest approach to the mass of a lensed light ray. It was shown that…

Astrophysics · Physics 2009-11-07 A. O. Petters

We investigate the predictions of Einsteinian Cubic Gravity (ECG) for the lensing effects due to supermassive black holes at the center of Milky Way and other galaxies. Working in the context of spherical symmetry, we obtain the metric…

General Relativity and Quantum Cosmology · Physics 2019-02-01 Mohammad Bagher Jahani Poshteh , Robert B. Mann

The effect of gravitational lensing on cosmic microwave background (CMB) anisotropies is investigated using the power spectrum approach. The lensing effect can be calculated in any cosmological model by specifying the evolution of…

Astrophysics · Physics 2009-10-28 Uros Seljak

It has been shown by Paczy\'nski that gravitational microlensing is potentially a useful method for detecting the dark constituents of the halo of our galaxy, if their mass lies in the approximate domain $10^{-6} < M/M_{\odot} < 10^{-1}$.…

Astrophysics · Physics 2008-02-03 Philippe Jetzer

We introduce the notion of defocusing gravitational lens considering a MACHO located behind a light source with respect to an observer. The consequence of defocusing effect is a temporal variability of star luminosity which produces a gap…

The strong gravitational lensing of a regular and rotating magnetic black hole in non-minimally coupled Einstein-Yang-Mills theory is studied. We find that, with the increase of any characteristic parameters of this black hole, such as the…

General Relativity and Quantum Cosmology · Physics 2023-10-16 Ruanjing Zhang , Jiliang Jing , Zhipeng Peng , Qihong Huang

We investigate the possibilities that pulsars act as the lens in gravitational microlensing events towards the galactic bulge or a spiral arm. Our estimation is based on expectant survey and observations of FAST (Five hundred meter Aperture…

High Energy Astrophysical Phenomena · Physics 2015-05-14 S. Dai , R. X. Xu , A. Esamdin

Traditional approaches to measuring the stellar mass function (MF) are fundamentally limited because objects are detected based on their luminosity, not their mass. These methods are thereby restricted to luminous and relatively nearby…

Astrophysics · Physics 2009-10-28 Andrew Gould

This work studies microlensing effects in strongly lensed gravitational wave (GW) signals corresponding to global minima images in galaxy-scale lenses. We find that stellar microlenses alone are unable to introduce noticeable wave effects…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-23 Ashish Kumar Meena

Recently Sumi et al. (2011) reported evidence for a large population of planetary-mass objects (PMOs) that are either unbound or orbit host stars in orbits > 10 AU. Their result was deduced from the statistical distribution of durations of…

In this letter, we investigate the strong gravitational lensing effects around two classes of rotating regular black holes, which behave as non-singular Minkowski core at the center. Starting from the null geodesic in the equatorial plane…

General Relativity and Quantum Cosmology · Physics 2025-01-07 Mingyu Guo , Menghe Wu , Hong Guo , Xiaomei Kuang , Fuyao Liu

Gravitational microlensing of quasars by stars in external galaxies can introduce fluctuations in the centroid of the ``point-like'' macro--images. The induced shifts are extremely small, on micro--arcsecond scales, below the limits of…

Astrophysics · Physics 2009-10-30 Geraint F. Lewis , Rodrigo A. Ibata

In some models dark energy is described by phantom scalar fields (scalar fields with "wrong" sign of the kinetic term in the lagrangian). In the current paper we study the effect of phantom scalar field and/or phantom electromagnetic field…

General Relativity and Quantum Cosmology · Physics 2013-05-31 Galin N. Gyulchev , Ivan Zh. Stefanov

We discuss the ratio of the angular diameter distances from the source to the lens, $D_{ds}$, and to the observer at present, $D_{s}$, for various dark energy models. It is well known that the difference of $D_s$s between the models is…

Astrophysics · Physics 2008-12-18 Seokcheon Lee , Kin-Wang Ng

This paper proposes a strategy for detecting the presence of a gravito-magnetic field due to the rotation of the galactic dark halo. Visible matter in galaxies rotates and dark matter, supposed to form a halo incorporating barionic matter,…

General Relativity and Quantum Cosmology · Physics 2018-12-19 Angelo Tartaglia

Our knowledge of the birth mass function of neutron stars and black holes is based on observations of binary systems but the binary evolution likely affects the final mass of the compact object. Gravitational microlensing allows us to…

Solar and Stellar Astrophysics · Physics 2021-07-30 P. Mroz , A. Udalski , L. Wyrzykowski , J. Skowron , R. Poleski , M. Szymanski , I. Soszynski , K. Ulaczyk
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