Astrometric Image Centroid Displacements due to Gravitational Microlensing by the Ellis Wormhole

Continuing work initiated in an earlier publication (Abe, ApJ, 725 (2010) 787), we study the gravitational microlensing effects of the Ellis wormhole in the weak-field limit. First, we find a suitable coordinate transformation, such that the lens equation and analytic expressions of the lensed image positions can become much simpler than the previous ones. Second, we prove that two images always appear for the weak-field lens by the Ellis wormhole. By using these analytic results, we discuss astrometric image centroid displacements due to gravitational microlensing by the Ellis wormhole. The astrometric image centroid trajectory by the Ellis wormhole is different from the standard one by a spherical lensing object that is expressed by the Schwarzschild metric. The anomalous shift of the image centroid by the Ellis wormhole lens is smaller than that by the Schwarzschild lens, provided that the impact parameter and the Einstein ring radius are the same. Therefore, the lensed image centroid by the Ellis wormhole moves slower. Such a difference, though it is very small, will be in principle applicable for detecting or constraining the Ellis wormhole by using future high-precision astrometry observations. In particular, the image centroid position gives us an additional information, so that the parameter degeneracy existing in photometric microlensing can be partially broken. The anomalous shift reaches the order of a few micro arcsec. if our galaxy hosts a wormhole with throat radius larger than $10^5$ km. When the source moves tangentially to the Einstein ring for instance, the maximum position shift of the image centroid by the Ellis wormhole is 0.18 normalized by the Einstein ring radius. For the same source trajectory, the maximum difference between the centroid displacement by the Ellis wormhole lens and that by the Schwarzschild one is -0.16 in the units of the Einstein radius.Comment: 29 pages, 6 figures, 2 tables, accepted by Ap

Volume 51, Number 2

Volume 51, Number 2. 6 pages including covers and advertisements. Miller, Sam The American Inferno Magner, Tom Canonized McNiel, Paul Nightshade\u27s Obbligato Rybarski, Michael McNeil, Paul Stew Ellis, J. Patrick Egan, Gerard Today Is Rain McNeil, Neil C. hope & consolation 1971 McNeil, Paul Outer Flight O\u27Neil, Charles J. Jr. Freedom O\u27Neil, Charles J. Jr. More or Less O\u27Neil, Charles J. Jr. As a Seed O\u27Neil, Charles J. Jr. Confectioner O\u27Neil, Charles J. Jr. For Existential Mariners Egan, Gerard Thursday Night Bortolot, Gary Balder Osborne, J.C. The Death of the American Achilles Bortolot, Gary Childhood\u27s Dream Piergrossi, Joe Egan, Gerard Rover, Dominic, O.P. THREE POEMS Ellis, J. Patrick Peter and The Aberration Ellis, J. Patrick Media #7 Nadeau, Larry A GOOD PASTIME Ellis, J. Patrick Secondary Reader VOL. 5 Egan, Gerard Downtown Yet Not Spring Piergrossi, Joe I Knew A Little Midget Man Egan, Gerard Rhys, Skyles Red Worm Kilgallen, Michael Quarter Hour Valentine McNeil, Paul 1969 Political O\u27Neil, Charles J. Jr. To Go Piergrossi, Jo

Parton Sum Rules and Improved Scaling Variable

The effect from quark masses and transversal motion on the Gottfried, Bjorken, and Ellis-Jaffe sum rules is examined by using a quark-parton model of nucleon structure functions based on an improved scaling variable. Its use results in corrections to the Gottfried, Bjorken, and Ellis-Jaffe sum rules. We use the Brodsky-Huang-Lepage prescription of light-cone wavefunctions to estimate the size of the corrections. We constrain our choice of parameters by the roughly known higher twist corrections to the Bjorken sum rule and find that the resulting corrections to the Gottfried and Ellis-Jaffe sum rules are relevant, though not large enough to explain the observed sum rule violations.Comment: latex, with 1 postscript figure, to be published in Phys.Lett.

Fearless: Adrienne Ellis

Taking the initiative to change college policies related to LGBTQ issues, restructuring a sustainable community garden in Gettysburg over the summer, and continually being motivated to change and challenge the powers that be through her love of people, Adrienne Ellis ’14 fearlessly fights for what she believes to help the people she loves— everybody. [excerpt