02.06.2013 Views

String Theory Demystified

String Theory Demystified

String Theory Demystified

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

50 <strong>String</strong> <strong>Theory</strong> Demystifi ed<br />

1<br />

αβ<br />

Using the fact that δ − h =− −hh<br />

δh<br />

fi nd an expression for the<br />

αβ<br />

2<br />

induced metric so that it can be eliminated from the action. This should<br />

allow you to recover the Nambu-Goto action.<br />

5. Consider an open string with free endpoints. Find the variation of the center<br />

of mass position of the string with τ by calculating<br />

1 π<br />

µ<br />

σ τ σ<br />

π ∫ d X ( , )<br />

0<br />

6. Find the conserved momentum of the open string with free endpoints by<br />

calculating<br />

π<br />

µ<br />

µ<br />

P T dσX ( τ, σ)<br />

= ∫ 0<br />

where the dot represents differentiation with respect to τ.

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!