degeneracy pressure

Scientific  

/ dĭ-jĕn′ər-ə-sē /

1. A pressure exerted by dense material consisting of fermions (such as electrons in a white dwarf star). This pressure is explained in terms of the Pauli exclusion principle, which requires that no two fermions be in the same quantum state. The more densely fermions are packed together and must share the same space, the more they must differ from each other in terms of their momentum. In turn, the greater the range in momentum, the greater the fraction of particles with high momentum, and these exert pressure on their surroundings.

2. See also neutron star white dwarf

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Example Sentences

Normally a quantum mechanical property called degeneracy pressure makes the electrons resist compression, adding support to the core.

From Scientific American

"A white dwarf no longer uses fusion. It is held together by degeneracy pressure. Extreme pressure. This is the only thing supporting it against collapse. This is also the only thing that keeps it from exploding."

From Los Angeles Times