- #1
Geonaut
- TL;DR Summary
- Quantum gravity and GUTs are nonrenormalizable theories, but does this actually mean that these theories must be flawed, or does it mean that renormalization must be a flawed concept, or is this a not actually a problem? If it is impossible to produce a renormalizable quantum gravity theory then shouldn't we view renormalization as an effective, but flawed resolution? Moreover, is this the only problem that we have with renormalization?
Quantum gravity theories and GUTs are nonrenormalizable theories, but does this actually mean that these theories must be flawed, or does it mean that renormalization must be a flawed concept, or is this not actually a problem? If it is impossible to produce a renormalizable quantum gravity theory then shouldn't we view renormalization as an effective, but flawed resolution? Moreover, is this the only problem that we have with renormalization?
I'd like to get as many perspectives of this topic as possible since I am not entirely sure how I feel about it. At the moment I believe that the fact that quantum gravity theories are nonrenormalizable is definitive evidence that there "ought to be a better way of doing things" as Richard Feynman stated in his lectures, but I know that there are many experienced physicists out there that I can learn from and so I'm reaching out.
The fact that gravity is not considered to be part of the standard model leads me to believe that the consensus here is that nonrenormalizable theories can't possibly be anything more than flawed descriptions of nature. This seems to be a reasonable conclusion considering that these theories force us to employ an infinite number of parameters (which seems absurd), but is this conclusion nothing more than an opinion? Aren't we still able to produce accuracy within these theories despite all of the ugliness? Moreover, couldn't we just as easily argue that it is renormalization itself that is flawed rather than these theories?
It appears that we must have running coupling constants in a realistic theory (although, now that I think about it, I think that I may recall Peskin talking about an alternative concept), but that's not what I'm trying to argue. When I say "renormalization" I'm referring to our methods that we use to remove ultraviolet divergences from quantum field theories. What I'm imagining is that a better scheme must exist that produces finite loop diagrams while maintaining the idea of bare and physical quantities that works just as well for nonrenormalizable theories. I think that this method must exist if we consider nonrenormalizable theories to be flawed since gravity is a nonrenormalizable force.
Would you agree with this conclusion of mine? I realize that I've asked many questions here, and I am interested in opinions on all of them, but opinions on any of them would be very appreciated.
I'd like to get as many perspectives of this topic as possible since I am not entirely sure how I feel about it. At the moment I believe that the fact that quantum gravity theories are nonrenormalizable is definitive evidence that there "ought to be a better way of doing things" as Richard Feynman stated in his lectures, but I know that there are many experienced physicists out there that I can learn from and so I'm reaching out.
The fact that gravity is not considered to be part of the standard model leads me to believe that the consensus here is that nonrenormalizable theories can't possibly be anything more than flawed descriptions of nature. This seems to be a reasonable conclusion considering that these theories force us to employ an infinite number of parameters (which seems absurd), but is this conclusion nothing more than an opinion? Aren't we still able to produce accuracy within these theories despite all of the ugliness? Moreover, couldn't we just as easily argue that it is renormalization itself that is flawed rather than these theories?
It appears that we must have running coupling constants in a realistic theory (although, now that I think about it, I think that I may recall Peskin talking about an alternative concept), but that's not what I'm trying to argue. When I say "renormalization" I'm referring to our methods that we use to remove ultraviolet divergences from quantum field theories. What I'm imagining is that a better scheme must exist that produces finite loop diagrams while maintaining the idea of bare and physical quantities that works just as well for nonrenormalizable theories. I think that this method must exist if we consider nonrenormalizable theories to be flawed since gravity is a nonrenormalizable force.
Would you agree with this conclusion of mine? I realize that I've asked many questions here, and I am interested in opinions on all of them, but opinions on any of them would be very appreciated.