Which force is responsible for the pressure support that keeps white dwarf stars from collapsing?

White dwarfs are the dense remnants of stars like the Sun, and they do not collapse further because of electron degeneracy pressure. This is not a separate fundamental force, but a quantum effect tied to the electromagnetic interactions and the Pauli exclusion principle. As matter is compressed, electrons resist occupying the same quantum state, creating pressure that can balance gravity. If enough mass is added, this support fails and the object may collapse further. The Chandrasekhar limit, about 1.4 times the mass of the Sun, marks the maximum stable mass of a white dwarf.