As I understand it, most of what we know about ancient mathematics comes from copies, quotations, and summaries by later scribes and scholars. Medieval Arab mathematicians in particular are given much credit for preserving the Greek classics:
In a general way it may be said that the Golden Age of Arabian mathematics was confined largely to the 9th and 10th centuries; that the world owes a great debt to Arab scholars for preserving and transmitting to posterity the classics of Greek mathematics; and that their work was chiefly that of transmission… (David E. Smith, History of Mathematics, 1958)
Given that so many of the ancient texts appear to be lost (even in reproduction), I am curious about which original texts by known authors have actually survived. And by "original texts", I mean the physical manuscripts that were dictated or handwritten by the authors themselves, or at least believed to be copied during their lifetimes rather than years or centuries later.
The earliest mathematical texts I know of don't fit these criteria. For example, the Rhind Papyrus (from perhaps 2000 BCE) is itself a copy of a much older work, and while the scribe's name is known, he was not the author. I'm not sure what the oldest surviving copy of the Zhou Bi Suan Jing (perhaps 1046 BCE) is, but in any case the identity of the author is unknown.
Do contemporary manuscripts exist for any named ancient mathematicians? For example, do we have any autographs of Archimedes, Euclid, Diophantus, or Pappus, or copies that were produced during their respective lifetimes?
I think that there are none.
Some data.
For Euclid, see:
and so on for MSS. of 11th and 12th centuries.
Also some extant fragments have been found on ancient papyri:
For Archimedes, see:
The recently discovered ancient Archimedes Palimpsest is a 10th-century Byzantine copy of an otherwise unknown work of Archimedes.