karma? not really.
That you can shape your reality because of your perception of it, yes. Reality at its core is a probability that collapses into an event upon observation. Being negative or positive or more importantly thinking that event will be either negative or positive can skew the probability.
So if you believe in karma then it works. If you don't believe in karma it doesn't matter because it still works, it just isn't called karma.
p.s. Physics is awesome