the answer is not really zero:
The notion that there are a zillion universes, whose individual properties are just a cosmic dice throw, is a story that has been told before and “raises the blood pressure of many physicists seriously,” as Dr. Livio put it. But the idea has rarely been mentioned by Dr. Witten, who is seen in the community as a symbol of the old Einsteinian ideal.
Dr. Witten said he was just doing his duty to explain what dark energy meant to physics.
“As for how I feel personally, I am not sure what to say,” he said in an e-mail message. “I wasn’t terribly enthusiastic the first, or even second, time I heard the proposal of a multiverse. But none of us were consulted when the universe was created.”
