Homing in on Axions?

Axions in Gauge Mediation

In supersymmetric theories, the presence of axions usually implies the existence of a non-compact, (pseudo)moduli space. In gauge mediated models, the axion would seem a particularly promising dark matter candidate. The cosmology of the moduli then constrains the gravitino mass and the axion decay constant; the former can’t be much below 10 MeV; the latter can’t be much larger than 10 GeV. Axin...

Homing in on helminths.

I am honored to give this lecture dedicated to the memory of Dr. Fred Soper, whose pioneering efforts against the insect vectors of malaria and yellow fever are legendary. Soper and his col leagues also played key roles in restoring the con cept of eradication to respectability after the col lapse of earlier campaigns to eradicate hookworm and yellow fever. When Soper was himself in vited to gi...

Axions In String Theory

In the context of string theory, axions appear to provide the most plausible solution of the strong CP problem. However, as has been known for a long time, in many stringbased models, the axion coupling parameter Fa is several orders of magnitude higher than the standard cosmological bounds. We re-examine this problem in a variety of models, showing that Fa is close to the GUT scale or above in...

On the Origin of Dark Matter Axions

We discuss the possible sources of dark matter axions in the early universe. In the standard thermal scenario, an axion string network forms at the Peccei-Quinn phase transition T ∼ fa and then radiatively decays into a cosmological background of axions; to be the dark matter, these axions must have a mass ma ∼ 100μeV with specified large uncertainties. An inflationary phase with a reheat tempe...

Homing in on L-selectin.