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Exact laws

A partial listing of physical conservation equations due to symmetry that are said to be exact laws , or more precisely have never been proven to be violated: Conservation Law Respective Noether symmetry invariance Number of dimensions Conservation of mass-energy Time-translation invariance Lorentz invariance symmetry 1 translation along time axis Conservation of linear momentum Space-translation invariance 3 translation along x , y , z directions Conservation of angular momentum Rotation invariance 3 rotation about x , y , z axes Conservation of CM (center-of-momentum) velocity Lorentz-boost invariance 3 Lorentz-boost along x , y , z directions Conservation of electric charge Gauge invariance 1⊗4 scalar field (1D) in 4D spacetime ( x , y , z  + time evolution) Conservation of color charge SU(3) Gauge invariance 3 r , g , b Conservation of weak isospin SU(2) L Gauge invariance 1 weak charge Conservation of probability Probability invaria...
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Conservation law

In physics, a conservation law states that a particular measurable property of an isolated physical system does not change as the system evolves over time. Exact conservation laws include conservation of energy, conservation of linear momentum, conservation of angular momentum, and conservation of electric charge. There are also many approximate conservation laws, which apply to such quantities as mass, parity, lepton number, baryon number, strangeness, hypercharge, etc. These quantities are conserved in certain classes of physics processes, but not in all. A local conservation law is usually expressed mathematically as a continuity equation, a partial differential equation which gives a relation between the amount of the quantity and the "transport" of that quantity. It states that the amount of the conserved quantity at a point or within a volume can only change by the amount of the quantity which flows in or out of the volume. From Noether's theorem, each conserva...
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Approximate laws

There are also approximate conservation laws. These are approximately true in particular situations, such as low speeds, short time scales, or certain interactions. Conservation of mechanical energy Conservation of rest mass Conservation of baryon number (See chiral anomaly and sphaleron) Conservation of lepton number (In the Standard Model) Conservation of flavor (violated by the weak interaction) Conservation of parity Invariance under charge conjugation Invariance under time reversal CP symmetry, the combination of charge conjugation and parity (equivalent to time reversal if CPT holds)
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