A problem posed by S. M. Ulam in 1940 has stimulated a long lasting interest in a particular stability of various types of equations and inequalities (difference, differential, functional, and integral). That issue is called sometimes Ulam’s type stability and is understood as follows: under what conditions is a function, satisfying an equation approximately, near a solution to that equation?

The first solution to the Ulam problem was obtained through a classical approach known from the fixed point theory, by iteration of a simple operator. Later, it has been shown that some fixed point theorems can be directly applied in investigations of Ulam’s type stability. Moreover, there is a converse relation; namely, some stability results yield the fixed point outcomes for function spaces.

This special issue is focused on the relations between the fixed point theory, Ulam’s type stability, and related subjects. Articles containing applications to the real-world situations are particularly welcome.

The authors are invited to submit original research papers as well as review articles that will stimulate the continuing efforts in investigations of that issue, its applications, and related problems.

Potential topics include, but are not limited to:

• Relations between Ulam’s type stability and fixed point results
• Fixed point and approximate fixed point theorems motivated or stimulated by Ulam’s type stability
• Relations between fixed points and approximate fixed points
• Algorithms for computing fixed points and approximate fixed points
• Various methods for proving Ulam’s type stability results
• Various types of stability (in the sense of Aoki, Bourgin, Găvruţa, Ger, Rassias, etc.) for equations and inequalities
• Hyperstability, superstability, asymptotic stability, and stability on restricted domains and in various spaces
• Applications and related problems