It is argued that learnability/E-stability is a necessary condition for a RE solution to be plausible. A class of linear models considered by Evans, G.W. and Honkapohja, S. [2001. Learning and Expectations in Macroeconomics, Princeton University Press.] is shown to include all models of the form...

We established the existence of weak solutions of the fourth-order elliptic equation of the form <Equation ID="Equa1"> <EquationSource Format="TEX">$$\begin{aligned} \Delta ^2 u -\Delta u + a(x)u=\lambda b(x) f(u) + \mu g (x, u), \qquad x \in \mathbb{R }^N, u \in H^2(\mathbb{R }^N), \end{aligned}$$</EquationSource> </Equation>where <InlineEquation ID="IEq3"> <EquationSource Format="TEX">$$\lambda $$</EquationSource> </InlineEquation> is a positive parameter, <InlineEquation ID="IEq4">...</inlineequation></equationsource></inlineequation></equationsource></equation>

In this paper, we prove the existence of infinitely many solutions to differential problems where both the equation and the conditions are Sturm–Liouville type. The approach is based on critical point theory. Copyright Springer Science+Business Media, LLC. 2012

Certain models of structural glasses ref. [1, 2] map onto random matrix models. These random matrix models have gaps in their eigenvalue distribution. It turns out that matrix models with gaps in their eigenvalue distributions have the unusual property of multiple solutions or minimas of the...

In the aftermath of the financial crisis, market efficiency is being heavily criticized. However, the volatility-based criticisms rely on false grounds as efficiency and speculative bubbles are compatible. Indeed, the efficient market model is about rationality and information, not about...

Criticizing the Efficient Market Hypothesis (EMH) on the basis of highly volatile asset prices is conceptually wrong as efficiency is about rationality and information, not about stability. Speculative bubbles are compatible with rational valuation, and hence with market efficiency. As rational...

It is well known that the concept of "determinacy"-a single stable solution-plays a major role in contemporary monetary policy analysis. But while determinacy is desirable, other things equal, it is not necessary for a solution to be plausible and is not sufficient for a solution to be...