universality means in phase transitions

Ising model

The Ising model describes ferromagnetism using interacting spins on a lattice

Bose–Einstein condensation of quasiparticles

Bose-Einstein condensation occurs at ultralow temperatures

Second law of thermodynamics

Entropy of isolated systems never decreases

Symmetry (physics)

Symmetry leads to energy conservation

Boltzmann's entropy formula

Boltzmann's entropy formula: S = k ln Ω

the Pauli exclusion principle forbids

Pauli exclusion principle forbids two identical fermions from occupying the same quantum state