Hovers Onno. The two short O’s of Indo-European

Research paper. — Draft version 2021-07, Internet publication — p. 1-23.There are a handful of sound-laws affected by PIE *o which apply very inconsistently, like Brugmann’s law in Indo-Iranian, Cowgill’s law in Greek, the vocalization of PIE *o by *h₂, Thurneysen-Havet’s law in Italic and other cases of Italic *a from PIE *o. There have been many attempts to define conditions for these laws to explain the inconsistencies, but they are plagued by counterexamples.
I will argue that these inconsistencies are cause by Indo-European having two short O vowels:
Close short “non-apophonic” *o̱ (/o/ or /ʊ/)
Open short “apophonic” *o (/ɔ/ or /ɒ/).
They show different ablaut patterns and are used in different parts of the derivative morphology of Indo-European. These O vowels behave differently under branch specific sound-laws in Anatolian, Indo-Iranian, Greek and Italic. The two O vowels also have different reflexes when adjacent to the laryngeal *h₂.