Integrating Gullstrand-Plainleve Coordinates in Kerr Metric

In summary, the conversation discusses the use of Gullstrand-plainleve coordinates in Kerr metric and the difficulty in understanding the integral aspect. The conversation also mentions the use of an online integral calculator to solve the integral and questions the accuracy of the results without incorporating the limits.
  • #1
stevebd1
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I'm looking at Gullstrand-plainleve coordinates in Kerr metric. While on the whole, it seems pretty straight forward, I found the integral aspect a little inaccessible. I've had a look at various web pages regarding integrals but to be honest, I don't know where to start with the following. Any insight would be appreciated.

[tex]\delta=a^2sin(2\theta)\int_r^{+\infty} \frac{v\Omega}{\varpi^2}dr[/tex]

where

[tex]\Omega=\frac{2Mar}{\rho^2(r^2+a^2)+2Ma^2rsin^2\theta}[/tex]

[tex]\varpi^2=r^2+a^2+\frac{2Mra^2}{\rho^2}sin^2\theta[/tex]

[tex]v=\frac{\sqrt{2Mr(r^2+a^2)}}{\rho^2}[/tex]

[tex]\rho^2=r^2+a^2cos^2\theta[/tex]
 
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  • #2
I used an online integral calculator (replacing r with x) which produced the following results-

http://www.majhost.com/gallery/stevebd/science/msp22530435753657184888_189.gif

Does this look right? (unfortunately it didn't have the means to incorporate the limits of r and +∞. What impact would that have on the results?).

online integral calculator-
http://integrals.wolfram.com/index.jsp
 
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FAQ: Integrating Gullstrand-Plainleve Coordinates in Kerr Metric

What are Gullstrand-Plainleve coordinates?

Gullstrand-Plainleve coordinates are a set of coordinates used to describe the spacetime around a rotating black hole in the Kerr metric. They are non-singular and provide a more intuitive representation of the curved spacetime.

How do Gullstrand-Plainleve coordinates differ from other coordinate systems?

Gullstrand-Plainleve coordinates differ from other coordinate systems in that they are non-singular at the event horizon of a black hole. They also have a "flow" that follows the path of a stationary observer, making them more intuitive to understand.

What is the significance of integrating Gullstrand-Plainleve coordinates in the Kerr metric?

Integrating Gullstrand-Plainleve coordinates in the Kerr metric allows us to better understand the behavior of spacetime around a rotating black hole. It also provides a more intuitive representation of the curved spacetime, making it easier to visualize and analyze.

How do Gullstrand-Plainleve coordinates help with studying black holes?

Gullstrand-Plainleve coordinates provide a simpler and more intuitive way to describe the spacetime around a black hole. This makes it easier to study and analyze the behavior of matter and light around black holes, which can give us insights into their properties and effects on the surrounding universe.

Are Gullstrand-Plainleve coordinates widely used in scientific research?

Yes, Gullstrand-Plainleve coordinates are widely used in scientific research, particularly in the field of general relativity and black hole physics. They have been used in numerous studies and have helped scientists gain a better understanding of the complex nature of black holes and the spacetime around them.

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