An expanding area of scientific exploration ...
In several areas of nuclear study ...
Another line of investigation has now been opened.
This realm (or field) of research is flourishing.
Смотреть больше слов в «Русско-английском научно-техническом словаре»
field of research, field of study, field of exploration, area of research, area of study, area of exploration
campo di ricerche
Forschungsbereich
champ d'études