Except for Bolyai, all mentioned above are indeed Jewish. Also all mentioned in your other comment (Fejér etc.) except Bollobás. Also Wigner, mentioned in another comment.
I stand corrected. I wrongly believed that many of these including Fejer and von Neumann were not Jewish.
I think the comparison with other populations such as Poland still seems to point out that something about Hungary in the 20th century was special, other than the presence of many Jewish people.
I think the comparison with other populations such as Poland still seems to point out that something about Hungary in the 20th century was special, other than the presence of many Jewish people.