When is SFT competitive?

When every $P$-flat ideal is flat

In this paper‎, ‎we study the class of rings in which every $P$-flat‎ ‎ideal is flat and which will be called $PFF$-rings‎. ‎In particular‎, ‎Von Neumann regular rings‎, ‎hereditary rings‎, ‎semi-hereditary ring‎, ‎PID and arithmetical rings are examples of $PFF$-rings‎. ‎In the context domain‎, ‎this notion coincide with‎ ‎Pr"{u}fer domain‎. ‎We provide necessary and sufficient conditions for‎...

Competitive Equilibrium when Preferences

We show the existence of a competitive equilibrium in an economy with many consumers whose preferences may change over time. The demand correspondence of an individual consumer is determined by the set of subgameperfect equilibrium outcomes in his or her intrapersonal game. For additively separable preferences with continuous period utility functions that are unbounded above, this demand corres...

Solvable SFT Inspired Phantom Model

We construct an exact analytic solution to the Friedman equations with a stringy inspired scalar matter and show explicitly an absence of the “Big Rip” singularity. The notable feature of this model is a wrong sign of the kinetic term and a special polynomial form of the effective tachyon potential. The method developed in the fivedimensional brane-world scenario is used. We show that the solut...

How competitive is competitive bidding?

Competitive Markets When Customers Anticipate Stockouts

How shoppers react to an empty shelf is an ongoing concern in naturally occurring markets. The anticipation of stockouts impacts where customers shop, which in turn affects optimal prices and inventory choices. In this paper we develop a differentiated product duopoly model of this situation. Theoretically, market outcomes hinge on the cost to the shopper of visiting a second seller after exper...