This man's eponymous unit is equal to a mole of photons, and his namesake effect is also known as gravitational redshift.
The constant kappa is sometimes known as this man's namesake constant, and that constant multiplied by the stress-energy tensor equals the Ricci tensor minus one-half the scalar curvature times the metric tensor, according to this man's namesake field equations.  This man's eponymous unit is equal to a mole of photons, and his namesake effect is also known as gravitational redshift. His namesake ring is also called a Chwolson Ring and is observed around celestial bodies as a result of gravitational lensing.  For 10 points, name this physicist who lends his name to a state of matter along with Satyendra Nath Bose.
The constant kappa is sometimes known as this man's namesake constant, and that constant multiplied by the stress-energy tensor equals the Ricci tensor minus one-half the scalar curvature times the metric tensor, according to this man's namesake field equations.  
Albert {Einstein}