{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

hw9 - J at the beginning of Chapter 2 useful but you should...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Physics 3002, Problem Set 9, due 4/15/09 Lam Hui 1. Ryden problem 7.7. In this problem, you are asked to show that the total physical area (measured today) of a sphere with a radius r (here, r refers to the coordinate radial distance, not a physical distance) is given by equation 7.24. You should be able to show this starting from the Robertson Walker metric given in equation 7.22. Note that in Ryden, d Ω 2 is a shorthand for 2 + ( sin θ ) 2 2 . 2. Ryden problem 7.8. Hints for the second part of this problem (i.e. deriva- tion of equation 7.54): 1. you might Fnd the discussion on intensity
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: J at the beginning of Chapter 2 useful, but you should also keep in mind that equation 2.2 for instance assumes Minkowski space, which is not what we have here; 2. the problem tells you that n is the number density of standard candles today, and that the candles are neither created nor destroyed as you go backward (or forward) in time – you should think carefully what this means for the proper number density versus comoving number density (one stays constant but the other changes with time)....
View Full Document

{[ snackBarMessage ]}

Ask a homework question - tutors are online