Terms starting with E
53 terms · page 3 of 3
Event Horizon
Astrophysics, Cosmology & Relativity
km or m (Boundary Radius)
The boundary surrounding a black hole beyond which escape velocity exceeds the speed of light, preventing any matter or signal from escaping.
R_s = 2 G M / c²
Exciton
Condensed Matter & Materials Physics
eV (Binding Energy)
A neutral quasiparticle consisting of a conduction electron bound to a valence band hole by electrostatic Coulomb attraction.
E_exciton = E_g - E_b (where E_b = μ e⁴ / (8 ε² h² n²))
Exoplanet
Astrophysics, Cosmology & Relativity
Earth Masses (M_⊕) or Jupiter Masses (M_J)
A planet situated outside the Solar System that orbits a star, stellar remnant, or brown dwarf.
Transit Depth ΔF / F = (R_planet / R_star)²
Expectation Value
Quantum & Atomic Physics
Same as measured quantity
The probabilistic average or expected value of many physical measurements performed on an ensemble of identically prepared quantum states.
⟨A⟩ = ∫ ψ* Â ψ dx / ∫ ψ* ψ dx
Extrinsic Semiconductor
Condensed Matter & Materials Physics
cm⁻³ (Dopant Carrier Density)
A semiconductor whose electrical conductivity is dominated by intentional impurity dopants rather than thermal excitation across the band gap.
n p = n_i² (Mass Action Law)