Difference between revisions of "Gravitational Lensing"

Revision as of 02:35, 6 December 2008

Questions in this category have been asked by PJ, MT and SR

• How can you use gravitational lensing to determine H0?
  • What is the deflection of light by sun using newtonian mechanics? (calculate it, do the integral)
  • Compare it with the GR result

• What kind of objects can cause gravitational lensing?
  • what's the smallest thing we know that causes lensing?

• "Do you know anything about Gravitational Lensing? Write down any equation related to lensing." (SR)
• How do you determine the magnification of a gravitationally lensed image from the lens equation? (SR)

• How would one calculate the deflection angle of light using GR? (SR)
• Write down the lens equation. (SR)
• What is a typical size of an Einstein radius? (RS? SR? I can't remember who asked.)
• In microlensing, how does one detect a lensing event, given that one does not see a clear Einstein ring? (SR,MT)
  • How is this effect related to the lensing potential? (SR, MT)

• Write down the lens equation for an isothermal sphere and a point mass. What is the Einstein radius?
  • How would you compute the magnification? How would you do this without any equations? (SR)

• What is the cross section for a stellar mass lensing event, a planet sized lensing event? Why do we see planet lensing events? (SR)

• What are the observational difficulties of weak lensing measurements? (MT)

Astrophysics