4,972 research outputs found
Phantom inflation and the "Big Trip"
Primordial inflation is regarded to be driven by a phantom field which is
here implemented as a scalar field satisfying an equation of state
, with . Being even aggravated by the weird properties
of phantom energy, this will pose a serious problem with the exit from the
inflationary phase. We argue however in favor of the speculation that a smooth
exit from the phantom inflationary phase can still be tentatively recovered by
considering a multiverse scenario where the primordial phantom universe would
travel in time toward a future universe filled with usual radiation, before
reaching the big rip. We call this transition the "big trip" and assume it to
take place with the help of some form of anthropic principle which chooses our
current universe as being the final destination of the time transition.Comment: 23 pages, 5 figures, LaTex, Phys. Lett. B (in press
Advertising for attention in a consumer search model
We model the idea that when consumers search for products, they first visit the firm whose advertising is more salient. The gains a firm derives from being visited early increase in search costs, so equilibrium advertising increases as search costs rise. This may result in lower firm profits when search costs increase. We extend the basic model by allowing for firm heterogeneity in advertising costs. Firms whose advertising is more salient and therefore raise attention more easily charge lower prices in equilibrium and obtain higher profits. As advertising cost asymmetries increase, aggregate profits increase, advertising falls and welfare increases.Advertising; attention; consumer search; saliency;
- …