How does one refer to a changed name in German?

Question

In America, there was a very famous investment writer named Benjamin Graham, who was Warren Buffett's teacher. But his birth name was actually Benjamin Grossbaum, a German name he changed during World War I.

What would be the term for the other name, Benjamin Grossbaum? Would it be "der ursprüngliche Name" (the original name)?

And how would one refer to the new name, Benjamin Graham?

Answer 1

I would use:

Geburtsname

for the original name as this is a legal term for a child's default surname (see § 1616 BGB). "Ursprünglicher Name" is okay, too.

For a newly adopted name changed later, I propose:

angenommener Name

(not sure whether translating this as "adopted name" is correct).

EDIT: AFAIK there's no fixed terminology for cases of name changing. Maybe this is due to the fact that changing its name in germany (and, i assume, in austria and switzerland) requires an administrative act. So, this isn't as easy as in common law countries. See Wikipedia on Namensrecht and on Legal Name.