The existence of small black holes, gravitational pits with masses no greater than two or three collapsed Suns, was recently established.

But the existence of primordial black holes has yet to be established.

The theory of relativity, for example, predicted the existence of black holes long before there was evidence to support the idea.

They also expect to confirm the existence of black holes.

Indeed, the existence of black holes is inferred only through their gravitational effects on other astronomical bodies.

Q. Were you surprised by some of the recent discoveries confirming the existence of black holes?

(May 2) First visual proof of existence of black holes.

It has been said that Hawking hoped to lose the bet, since so much of his own work depended upon the existence of black holes.

The existence of black holes in the universe is well supported, both theoretically and by astronomical observation.

A12 New evidence was reported for the existence of black holes.