The idea that we might be living in a computer simulation began to gain popularity when Elon Musk began talking about it publicly. I believe this paper by Nick Bostrom was the one that really kicked off this discussion.

The tl;dr of the paper is: we probably are living in a simulation, but there's no way to be sure, and it doesn't have any observable impact on our lives.

Like most papers that postulate on metaphysics, I'm not really convinced by the author's claims. We wouldn't have derived most of the laws of physics by deduction alone, so it's unlikely the simple deductive reasoning the author uses is giving us an accurate picture of the nature of reality.