Definitions

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. The condition of being extremal

Etymologies

Sorry, no etymologies found.

Examples

  • In an extremal black hole, where all of the energy comes from the electric field itself, the two horizons coincide: we have r+ = r - (extremality).

    Where Does the Entropy Go?

  • We found that the volume of spacetime between the two horizons approached a smooth limit as the charge was increased, but discontinuously disappeared exactly at extremality.

    Cosmic Variance

  • In other words, the approach to extremality is not continuous, as the non-extremal Reissner-Nordström solution splits into two spacetimes at extremality: an extremal black hole and a disconnected $AdS$ space.

    Cosmic Variance

  • Hawking, Horowitz and Ross found that the entropy of a charged black hole approached a smooth limit as the charge was increased, but discontinuously went to zero exactly at extremality.

    Cosmic Variance

  • Quick question: if the limit of approaching extremality is discontinuous, doesn't that mean that the exactly extremal space, the one with zero entropy, is unstable to infinitesimal perturbations, and therefore unphysical?

    Cosmic Variance

  • But Matt, Lisa and I stumbled across an interesting miracle of curved spacetime, which I think some people recognized but certainly isn't widely appreciated: as you creep up on extremality, increasing the charge of the black hole while keeping its mass fixed, and therefore driving

    Cosmic Variance

  • But Matt, Lisa and I stumbled across an interesting miracle of curved spacetime, which I think some people recognized but certainly isn’t widely appreciated: as you creep up on extremality, increasing the charge of the black hole while keeping its mass fixed, and therefore driving r - ever closer to r+, the spacetime volume of the region in between them does not go to zero.

    Where Does the Entropy Go?

  • The higher variance implies that it is easier to find more extreme men than more extreme women, regardless of the exact quantity that defines the extremality.”

    Switch Hitting: Part II

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