This paper explores equilibrium and optimal matching behavior in constant returns to scale search economies with heterogeneous agents. We show that optimal matching behavior may involve a nontrivial limit cycle, and that there may exist a continuum of cyclical perfect foresight equilibria. These results hold for a generic set of parameter values. They are due to a trading externality (Diamond 1...

For a given differential system, a limit cycle is a periodic orbit isolated in the set of all its periodic orbits. Within the qualitative theory of differential systems, the study of their limit cycles is one of the main topics. Many questions are considered on the limit cycles of the differential systems in R2. Thus, one of the main lines of research for such systems is the study of how many l...

If Γ 1 and Γ 2 are limit groups and S ⊂ Γ 1 × Γ 2 is of type FP 2 then S has a subgroup of finite index that is a product of at most two limit groups.

We study, with various methods, the high temperature phase transition for the N-component φ 4 theory in the large N limit. Our results fully confirm a previous investigation of the problem, for arbitrary N , with the method of the average potential. The phase transition is of the second order with an effectively three-dimensional critical behaviour.

This paper shows how globally attractive limit cycle oscillations can be induced in a system with a nonlinear feedback element. Based on the same principle as the Van der Pol oscillator, the feedback behaves as a negative damping for low velocities but as an ordinary damper for high velocities. This nonlinear damper can be physically implemented with a continuous variable transmission and a spr...

We analyze the Higgs sector in the Next-to-Minimal Supersymmetric Standard Model, emphasizing the possibility of a light CP-odd scalar (axion) in the spectrum. We compute the coupling of the Standard-Model-like Higgs boson to a pair of axions, and show that it can be large enough to modify the Higgs branching fractions, with a significant impact on the Higgs searches. We delineate the range of ...

The problem of limit cycles for Kolmogorov model is interesting and significant both in theory and applications. Our work is concerned with limit cycles bifurcations problem for a class of quartic Kolmogorov model with two positive singular points (i.e. (1, 2) and (2, 1)). The investigated model is symmetrical with regard to y = x. We show that each one of points (1, 2) and (2, 1) can bifurcate...