Black brane

Source: Wikipedia, the free encyclopedia.

In

which?] that generalizes a black hole solution but it is also extended—and translationally symmetric—in p additional spatial dimensions. That type of solution would be called a black p-brane.[1]

In

However, many physicists tend to define a black brane separate from a black hole, making the distinction that the singularity of a black brane is not a point like a black hole, but instead a higher dimensional object.

A BPS black brane is similar to a BPS black hole. They both have electric charges. Some BPS black branes have magnetic charges.[4]

The metric for a black p-brane in a n-dimensional spacetime is:

where:

  • η is the (p + 1)-
    Minkowski metric
    with signature (−, +, +, +, ...),
  • σ are the coordinates for the worldsheet of the black p-brane,
  • u is its four-velocity,
  • r is the radial coordinate and,
  • Ω is the metric for a (n − p − 2)-sphere, surrounding the brane.

Curvatures

When .

The Ricci Tensor becomes , .

The Ricci Scalar becomes .

Where , are the Ricci Tensor and Ricci scalar of the metric .

Black string

A black string is a higher

topologically equivalent to S2 × S1 and spacetime
is asymptotically Md−1 × S1.

Perturbations of black string solutions were found to be unstable for L (the length around S1) greater than some threshold L′. The full non-linear evolution of a black string beyond this threshold might result in a black string breaking up into separate black holes which would coalesce into a single black hole. This scenario seems unlikely because it was realized a black string could not pinch off in finite time, shrinking S2 to a point and then evolving to some Kaluza–Klein black hole. When perturbed, the black string would settle into a stable, static non-uniform black string state.

Kaluza–Klein black hole

A Kaluza–Klein black hole is a black brane (generalisation of a

Kaluza–Klein space, i.e. higher-dimensional spacetime with compact dimensions. They may also be called KK black holes.[5]

See also

References

  1. ^ "black brane in nLab". ncatlab.org. Retrieved 2017-07-18.
  2. OCLC 647880066
    .
  3. ^ "String theory answers". superstringtheory.com. Archived from the original on 2018-01-11. Retrieved 2017-07-18.
  4. OCLC 773812736
    .
  5. ^ Obers (2009), p. 212–213

Bibliography

  • Obers, N.A. (2009). "Black Holes in Higher-Dimensional Gravity". Physics of Black Holes. Lecture Notes in Physics. Vol. 769. pp. 211–258.
    S2CID 14911870
    .