Oskar Morgenstern: German
Ferdinand Porsche: German
Valier: never heard of this guy until I looked him up just now; a true Austrian - albeit born in Italy and worked in Germany. Damned shame he died so young.
Karl Popper: Jew
Ludwig Boltzmann: the second real Austrian on this list.
Christian Doppler: another real Austrian...
Ernst Mach: Volksdeutsche from what is now Czech Republic.
Wolfgang Pauli: Czech-Jew, and related to Mach.
Kurt Gödel: German AMERICAN, F YEAH!! :)
Gregor Mendel: Volksdeutsche, from Silesia (now part of Czech Republic)
So I see only 3 Austrian on this list!
P.S. the Brits/Finns/Ukrainians/Russians always make a good joke at Germans' expense, but Austria always gets a free pass... I'm trying to right that wrong! :)
If you are going to assert that Jews cannot be Austrian, you may as well go all the way and give Hitler credit for being Austrian.
Due to changing borders, I'm not attributing Austria-Hungary's borders, but people who held Austrian citizenship after the breakup or resided in Austria proper were Austrian, regardless of where they were born. I'm ignoring the notion that Jews can't Austrian.
Of course, since he was born into the Austro-Hungarian Empire, and studied in Graz, we might as well let the Austrians take credit, as the Austrians really need it (what's Austria's greatest accomplishment? convincing the world that Mozart is Austrian, and Hitler is German!)
But really, he did his best work as an American, so USA! USA! USA! :)