Analyticity of a class of degenerate evolution equations on the canonical simplex of Rd\R^d arising from Fleming--Viot processes

We study the analyticity of the semigroups generated by a class of degenerate second order differential operators in the space $C(S_d)$, where $S_d$ is the canonical simplex of $\R^d$. The semigroups arise from the theory of Fleming--Viot processes in population genetics.Comment: 32 page

Frequently hypercyclic translation semigroups

Frequent hypercyclicity for translation $C_0$-semigroups on weighted spaces of continuous functions is investigated. The results are achieved by establishing an analogy between frequent hypercyclicity for the translation semigroup and for weighted pseudo-shifts and by characterizing frequent hypercyclic weighted pseudo-shifts in spaces of vanishing sequences. Frequent hypercylic translation semigroups in weighted $L^p$-spaces are also characterized

Associated weights for spaces of p-integrable entire functions

[EN] In analogy to the notion of associated weights for weighted spaces of analytic functions with sup-norms, p-associated weights are introduced for spaces of entire p-integrable functions, 1 <= p < infinity. As an application, necessary conditions for the boundedness of composition operators acting between general Fock type spaces are provedThe research of Bonet was partially supported by the projects MTM2016-76647-P and GV Prometeo/2017/102 (Spain).Bonet Solves, JA.; Mangino, EM. (2020). Associated weights for spaces of p-integrable entire functions. Quaestiones Mathematicae. 43(5/6):747-760. https://doi.org/10.2989/16073606.2019.1605420S747760435/

Generation of semigroups associated to strongly coupled elliptic operator in Lp(Rd;Rm)L^p(\mathbb R^d;\mathbb R^m)

A class of vector-valued elliptic operators with unbounded coefficients, coupled up to the second-order is investigated in the Lebesgue space $L^p(\mathbb R^d;\mathbb R^m)$ with $p \in (1,\infty)$, providing sufficient conditions for the generation of an analytic $C_0$-semigroup $T(t)$. Under further assumptions, a characterization of the domain of the infinitesimal generator is given

Missing Data and IRT Item Parameter Estimation

Non-randomly missing data has theoretically different implications for item parameter estimation depending on whether joint maximum likelihood or marginal maximum likelihood methods are used in the estimation. The objective of this paper is to illustrate what potentially can happen, under these estimation procedures, when there is an association between ability and the absence of response. In this example, data is missing because some students, particularly low-ability students, did not complete the test