Magnification Cross Sections for the Elliptic Umbilic Caustic Surface

In gravitational lensing, magnification cross sections characterize the probability that a light source will have magnification greater than some fixed value, which is useful in a variety of applications. The (area) cross section is known to scale as <inline-formula> <math display="inl...

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Main Authors: Amir B. Aazami, Charles R. Keeton, Arlie O. Petters
Format: Article
Language:English
Published: MDPI AG 2019-07-01
Series:Universe
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Online Access:https://www.mdpi.com/2218-1997/5/7/161
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author Amir B. Aazami
Charles R. Keeton
Arlie O. Petters
author_facet Amir B. Aazami
Charles R. Keeton
Arlie O. Petters
author_sort Amir B. Aazami
collection DOAJ
description In gravitational lensing, magnification cross sections characterize the probability that a light source will have magnification greater than some fixed value, which is useful in a variety of applications. The (area) cross section is known to scale as <inline-formula> <math display="inline"> <semantics> <msup> <mi>&#956;</mi> <mrow> <mo>&#8722;</mo> <mn>2</mn> </mrow> </msup> </semantics> </math> </inline-formula> for fold caustics and <inline-formula> <math display="inline"> <semantics> <msup> <mi>&#956;</mi> <mrow> <mo>&#8722;</mo> <mn>2.5</mn> </mrow> </msup> </semantics> </math> </inline-formula> for cusp caustics. We aim to extend the results to higher-order caustic singularities, focusing on the elliptic umbilic, which can be manifested in lensing systems with two or three galaxies. The elliptic umbilic has a caustic surface, and we show that the volume cross section scales as <inline-formula> <math display="inline"> <semantics> <msup> <mrow> <mi>&#956;</mi> </mrow> <mrow> <mo>&#8722;</mo> <mn>2.5</mn> </mrow> </msup> </semantics> </math> </inline-formula> in the two-image region and <inline-formula> <math display="inline"> <semantics> <msup> <mrow> <mi>&#956;</mi> </mrow> <mrow> <mo>&#8722;</mo> <mn>2</mn> </mrow> </msup> </semantics> </math> </inline-formula> in the four-image region, where <inline-formula> <math display="inline"> <semantics> <mi>&#956;</mi> </semantics> </math> </inline-formula> is the total unsigned magnification. In both cases our results are supported both numerically and analytically.
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spelling doaj.art-6b04df3328a34aac8c20355022ecb37c2022-12-22T04:23:43ZengMDPI AGUniverse2218-19972019-07-015716110.3390/universe5070161universe5070161Magnification Cross Sections for the Elliptic Umbilic Caustic SurfaceAmir B. Aazami0Charles R. Keeton1Arlie O. Petters2Department of Mathematics and Computer Science, Clark University, Worcester, MA 01610, USADepartment of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08854-8019, USADepartments of Mathematics and Physics, Duke University, Science Drive, Durham, NC 27708-0320, USAIn gravitational lensing, magnification cross sections characterize the probability that a light source will have magnification greater than some fixed value, which is useful in a variety of applications. The (area) cross section is known to scale as <inline-formula> <math display="inline"> <semantics> <msup> <mi>&#956;</mi> <mrow> <mo>&#8722;</mo> <mn>2</mn> </mrow> </msup> </semantics> </math> </inline-formula> for fold caustics and <inline-formula> <math display="inline"> <semantics> <msup> <mi>&#956;</mi> <mrow> <mo>&#8722;</mo> <mn>2.5</mn> </mrow> </msup> </semantics> </math> </inline-formula> for cusp caustics. We aim to extend the results to higher-order caustic singularities, focusing on the elliptic umbilic, which can be manifested in lensing systems with two or three galaxies. The elliptic umbilic has a caustic surface, and we show that the volume cross section scales as <inline-formula> <math display="inline"> <semantics> <msup> <mrow> <mi>&#956;</mi> </mrow> <mrow> <mo>&#8722;</mo> <mn>2.5</mn> </mrow> </msup> </semantics> </math> </inline-formula> in the two-image region and <inline-formula> <math display="inline"> <semantics> <msup> <mrow> <mi>&#956;</mi> </mrow> <mrow> <mo>&#8722;</mo> <mn>2</mn> </mrow> </msup> </semantics> </math> </inline-formula> in the four-image region, where <inline-formula> <math display="inline"> <semantics> <mi>&#956;</mi> </semantics> </math> </inline-formula> is the total unsigned magnification. In both cases our results are supported both numerically and analytically.https://www.mdpi.com/2218-1997/5/7/161strong gravitational lensingmagnification cross sectionscaustics
spellingShingle Amir B. Aazami
Charles R. Keeton
Arlie O. Petters
Magnification Cross Sections for the Elliptic Umbilic Caustic Surface
Universe
strong gravitational lensing
magnification cross sections
caustics
title Magnification Cross Sections for the Elliptic Umbilic Caustic Surface
title_full Magnification Cross Sections for the Elliptic Umbilic Caustic Surface
title_fullStr Magnification Cross Sections for the Elliptic Umbilic Caustic Surface
title_full_unstemmed Magnification Cross Sections for the Elliptic Umbilic Caustic Surface
title_short Magnification Cross Sections for the Elliptic Umbilic Caustic Surface
title_sort magnification cross sections for the elliptic umbilic caustic surface
topic strong gravitational lensing
magnification cross sections
caustics
url https://www.mdpi.com/2218-1997/5/7/161
work_keys_str_mv AT amirbaazami magnificationcrosssectionsfortheellipticumbiliccausticsurface
AT charlesrkeeton magnificationcrosssectionsfortheellipticumbiliccausticsurface
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