The book contains a collection of 21 original research papers which report on recent developments in various fields of nonlinear analysis. The collection covers a large variety of topics ranging from abstract fields such as algebraic topology, functional analysis, operator theory, spectral theory, analysis on manifolds, partial differential equations, boundary value problems, geometry of Banach spaces, measure theory, variational calculus, and integral equations, to more application-oriented fields like control theory, numerical analysis, mathematical physics, mathematical economy, and financial mathematics. The book is addressed to all specialists interested in nonlinear functional analysis and its applications, but also to postgraduate students who want to get in touch with this important field of modern analysis. It is dedicated to Alfonso Vignoli who has essentially contributed to the field, on the occasion of his sixtieth birthday.

Alfonso Vignoli - the Researcher, Teacher, and Friend.- How to Make Use of the Solution Set to Solve Boundary Value Problems.- On the Unique Solvability of Hammerstein Integral Equations with Non-Symmetric Kernels.- The Invariance of Domain for C1Fredholm Maps of Index Zero.- Positive Eigenfunctions for Some Unbounded Differential Operators.- Some Geometrical Properties of Rearrangement Invariant Spaces.- Strong Surjections and Nearness.- On the Vanishing Viscosity Approximation of a Time Dependent Hamilton-Jacobi Equation.- Some Remarks on a Nonlinear Model of Competitive Equilibrium.- Almost Discrete Convergence.- Nonlinear Stability of Eigenvalues of Compact Self-Adjoint Operators.- A Bifurcation Theorem for Lagrangian Intersections.- La valutazione di opzioni implicite nei mutui bancari.- Continuity of Near-Duality Maps and Characterizations of Ideal Spaces of Measurable Functions.- A Spectral Theory for Semilinear Operators and its Applications.- Feedback Stability of Closed Sets for Nonlinear Control Systems.- Two Mechanical Systems and Equivariant Degree.- On the Semilinear Dirichlet Problem for a Class of Nonlocal Operators Generating Dirichlet Forms.- Bifurcation for One-Parameter Families of Scalar Maps: A Geometric Viewpoint.- Mountain Pass and Linking Type Solutions for Semilinear Dirichlet Forms.- Self-Similar Measures in Quasi-Metric Spaces.- C1-Fredholm Maps and Bifurcation for Quasilinear Elliptic Equations on$${\mathbb{R}^n}
$$.