Cosmological consequences of particle creation during inflation

Particle creation during inflation is considered. It could be important for species whose interaction is of gravitational strength or weaker. A complete but economical formalism is given for spin-zero and spin-half particles, and the particle abundance is estimated on the assumption that the particle mass in the early universe is of order the Hubble parameter $H$. It is roughly the same for both spins, and it is argued that the same estimate should hold for higher spin particles in particular the gravitino. The abundance is bigger than that from the usual particle collision mechanism if the inflationary energy scale is of order $10^{16} GeV$, but not if it is much lower.Comment: 17 pages, no Figure

Novel Catalysts for low temperature synthesis of single wall carbon nanotubes

Low temperature single wall carbon nanotubes (SWCNT) synthesis is attractive as it would allow their synthesis to be compatible with microelectronics (below 500°C) or biomolecular electronics (160°C). We show that the presence of oxygen, introduced in the form of metal oxides, allows metals not normally associated with nanotubes synthesis to become active for the synthesis of SWCNT using laser ablation. Further, the results show metals with low melting points can be used, enabling SWCNT to be sythesized at low temperature (down to room temperature). At these low temperatures their nucleation cannot be explained via fullerene nucleation. We suggest a growth mechanism that places a stable oxidiced ring as the root cause for the growth of SWCNT