He came to Indiana University in 1977, completing his PhD in 1981 under the direction of Madan Lal Puri.
Before moving to New York, Ralescu was an assistant professor in the Division of Applied Mathematics at Brown University (1981–1984).
His research themes are varied, and include the fields of asymptotic theory of perturbed empirical and quantile processes, nonparametric density estimation and Stein estimation (see James–Stein estimator), as well as work in collaboration with Dr. A. Cassvan in connection to techniques using brain auditory evoked potentials (BAEP).
[1] Ralescu is an Elected Fellow of the International Statistical Institute.
His hobbies include rare book collecting[citation needed] and bridge.