An enhanced binding of an N -particle system interacting through a scalar bose field is investigated, where N ≥ 2. It is not assumed that this system has a ground state for a zero coupling. It is shown, however, that there exists a ground state for a sufficiently large values of coupling constants. When the coupling constant is sufficiently large, N particles are bound to each other by the scal...

The HVZ theorem is proven for the pseudorelativistic N electron Jansen-Hess operator (2 ≤ N ≤ Z) which acts on the spinor Hilbert space A(H1(R)⊗C) where A denotes antisymmetrization with respect to particle exchange. This ’no pair’ operator results from the decoupling of the electron and positron degrees of freedom up to second order in the central potential strength γ = Ze. 2000 Mathematics Su...

Postcopulatory competition between males, in the form of sperm competition, is a widespread phenomenon in many animal species. The extent to which sperm competition has been an important selective pressure during human evolution remains controversial, however. The authors review critically the evidence that human males and females have psychological, behavioral, and physiological adaptations th...

We provide a very general result that identifies the essential spectrum of broad classes of operators as exactly equal to the closure of the union of the spectra of suitable limits at infinity. Included is a new result on the essential spectra when potentials are asymptotic to isospectral tori. We also recover with a unified framework the HVZ theorem and Krein’s results on orthogonal polynomial...

Recently, interest has grown in agents that negotiate with people: to teach negotiation, to negotiate on behalf of people, and as a challenge problem to advance artificial social intelligence. Humans negotiate differently from algorithmic approaches to negotiation: people are not purely self-interested but place considerable weight on norms like fairness; people exchange information about their...