Weakless universe

The Weakless Universe is a hypothetical universe that contains no weak interactions, but is otherwise very similar to our own universe.

Motivation

The strength of the weak interaction is an outstanding problem in modern particle physics. A theory should ideally explain why the weak interaction is 32 orders of magnitude stronger than gravity; this is known as the hierachy problem in gauge theory.

Historically, one possible explanation of this (among other constraints on quantum theories) is to use the anthropic principle. That is, our universe's fundamental particles have a relatively strong weak interaction, because otherwise we would not be around at all. We, as observers, could not have existed if the weak force was weaker.

The hypothetical weak interaction-less universe is meant to serve as a counter example to this claim.

Construction

The weakless universe is designed such that it dynamics match those of our own as much as possible; this avoids difficult calculations of new dynamical systems.

In particular, weakless nuclear physics and chemistry is claimed to be identical to standard nuclear physics and chemistry. The dynamics of the weakless universe includes a period of big bang nuclear synthesis, star formation, stars that burn for billions of years, stellar nuclear synthesis of heavy elements and also supernovae that distribute the heavy elements into the interstellar medium.

Argument

The hypothetical existence of the constructed phenomena is taken to be sufficient for the development of organisms in the weakless universe capable of making observations of the strength of the weak interaction. This completes the argument.

The argument might be defeated if there were some hitherto unknown dependency of eg. neurobiology on the effects of weak interactions.

References

• A Universe without Weak interactions - Roni Harnik, Graham Kribs, Gilad Perez - Phys.Rev.D74:035006,2006.