Constants of nature in the early universe

[windy miller]

As I understand it, in string theory the constants of nature can taken on a huge different number of possible values and when the universe cools after the big bang these constants of nature get locked in as it were and become , well constants.

My question is, what if we discard string theory - are there any non string theory reasons to think the constants of nature, like the cosmological constant or the masses of particles, could be different to what they are?

 

[Chronos]

Certain relationships appear to exist that suggest [at least to me] the values of natural constants are relational in some fundamental sense. Assuming the constants of nature are emergent properties of the universe, it seems reasonable to suspect the values assumed by the first constants to emerge affected the values available to constants that subsequently emerged. I personally prefer such an answer over anthropics to questions regarding the apparent fine tuning of natural constants.

 

[windy miller]

Any papers out there promoting this idea? i give you are thinking of CNS or is there some other framework that support this?

 

[Kevin McHugh]

I thought the constants were fixed by the initial conditions of the state of the universe prior to inflation?

 

[Chalnoth]

As I understand it, in string theory the constants of nature can taken on a huge different number of possible values and when the universe cools after the big bang these constants of nature get locked in as it were and become , well constants.

My question is, what if we discard string theory - are there any non string theory reasons to think the constants of nature, like the cosmological constant or the masses of particles, could be different to what they are?

Yes. Essentially any grand-unified theory has this property.

One way of describing the broad features of the standard model of particle physics is by describing the symmetry groups it conforms to:
SU(3) x SU(2) x U(1)

These are, in order, the strong nuclear force, the weak nuclear force*, and the electromagnetic force. Physicists have been trying to come up with a single equation of motion following a single symmetry that explains the above. You can read a bit more details on some of the possibilities that have been examined here. But the fundamental point is that this higher-order symmetry had to be broken by some process, and usually that means that the symmetry could have been broken in other ways as well.

* This isn't completely correct: the weak and electromagnetic forces are mixed in a sense, so this description is a bit oversimplified. But it's good enough for the point I'm trying to make.

 

[Chronos]

No mainstream theory expressing hierarchical dependencies between fundament natural constants has yet appeared in the literature, afaik, The Koide equation is a limited example of one such attempt, but, smacks more of numerology than any physical import. The widespread practice of substituting dimensionless constants as a mathematical convenience, however, also smacks of numerology without conceding an assumption of relational validity between dimensionless constants and their empirical constituents. The best justification we can offer is a proponderance of evidence case from the observed consistency of dimensionless constants across cosmic time scales.