Hubble law vs Hubble's law

Hubble law and Hubble's law both are nouns.

Word	Noun	Adjective	Verb	Adverb
Hubble law	Yes	No	No	No
Hubble's law	Yes	No	No	No

As nouns, Hubble law and Hubble's law are synonyms defined as:

Hubble law and Hubble's law: (astronomy) the generalization that the speed of recession of distant galaxies (the red shift) is proportional to their distance from the observer

Hubble law (noun)	Hubble's law (noun)
(astronomy) the generalization that the speed of recession of distant galaxies (the red shift) is proportional to their distance from the observer	(astronomy) the generalization that the speed of recession of distant galaxies (the red shift) is proportional to their distance from the observer