We study three types of asymptotic behaviors in commutative algebra: limit of length of
local cohomology of thickenings, degrees of generators of socle of local cohomology of thickenings
and limit of F-pure thresholds. In Chapter 1 and 2 we will review necessary background and
motivations for the questions that we study. Chapter 3 will be devoted to the study of limit of
length of local cohomology of determinantal thickenings, where the author proves the existence
of such limits and find closed formulae for the generalized multiplicities of interest (this is
the content of (1)). Chapter 4 is joint work with Perlman (this is the content of (2)). We
will continue the investigation of local cohomology modules of determinantal thickenings, this
time we turn our attention to their socle. In particular, precise formulas of socle degrees are
proved. Finally, in Chapter 5 we will study singularities of pairs in both zero and positive
characteristic, where the main object of study is linkage of ideals, and the relation of least
critical exponents of a pair and its linkage has been proved. The author also applies this result
to deduce corresponding results on F-pure thresholds and log canonical thresholds (this is the
content of (3)).