Thread 16754380

Since we do not live in anti-/desitter space, but minkowski space, string "theory" will never describe the universe we live in.

Therefore GR minkowski space is the best theory and there is no conservation of energy nor momentum with GR in this space.

So why do we need "dark energy" to account for the expansion of space? Why would the energy have to come and go somewhere??

Most people think we live in De Sitter space, not Minkowski space i.e. positive cosmological constant. It's conceivable that we somehow measure the CC wrongly, or that our "positive" curvature is only a local effect and the rest of the universe is Anti-De Sitter. String theory with De Sitter also hasn't been ruled out.

>>16754388
Susskin already said we simply do not live in the kind of world string theory was developed for. It's only true we might live in desitter space if you think dark energy and expanding universe is the same thing

>>16754394
Well sussy boy is just one fag. What's your level of physics/maths education, if I may be so bold as to ask?

>>16754395
in physics? only a masters

>>16754380 (OP)
dark energy is there as the best fit to our current cosmological data
>>16754388
similarly, the universe could be approximately de Sitter right now, but in a meta-stable way and then decay. It'd be hard to rule out desu. Some string pheno people, like Thomas van Riet believe this I think.

That being said, we don't need our universe to be asymptotically de Sitter for AdS/CFT to be interesting. It's still a way to understand what a theory of quantum gravity looks like, and/or theories of strongly interacting QFTs look like. So we can learn a bunch of either of those.

>>16754380 (OP)
No one ever seriously believed in String Theory. The guy who thought it up just had pull with the tenure committee, so they were able to pressure everyone into endorsing it. It's one of the best examples for why tenure as a concept should be outlawed.