ɪnðə sˈeɪm pˈiəɹɪəd kˈæslɚ, ɪn kəlˌæbɚɹˈeɪʃən wɪð ɹˈeɪmənd stˈoːɹə, dɪvˈɛləpt ðə dʒˌiːoʊmˈɛtɹɪkəl sˈɛɾɪŋ fɚðə bˌiːˌɑːɹɹˌɛstˈiː tɹænsfoːɹmˈeɪʃənz fɚðə kwˌɔntᵻzˈeɪʃən ʌv ɡˈeɪdʒ θˈiəɹiz.
In the same period Kastler, in collaboration with Raymond Stora, developed the geometrical setting for the BRST transformations for the quantization of gauge theories.