Research Interests

My astronomical/astrophysical research interests mainly center on:

  1. Physical Cosmology
  2. Cosmic Structure Formation
  3. Large Scale Distribution of Galaxies

while I have a keen interest in various mathematical topics, in particular:

  1. Stochastic Geometry (Voronoi & Delaunay tessellations, spatial point processes)
  2. Stochastic Random Fields

Fascinated by the origin and structure of the Universe as well as by the nobility and serenity of geometry I find it inspiring to see that the Universe in more than one way resembles the Academia of Plato, that venerable institution devoted to learning, seeking to uncover the secrets of the world and our existence, over whose door it was said to be written

``Let no one unversed in geometry enter here ''

photograph: Rien van de Weygaert
(Academia Platon, Athens, April 2001)

Research Project descriptions:

      Delaunay Tessellation Field Reconstruction

                                          II.    images DTFE analysis 2dFGRS

                                          III.    images DTFE analysis SDSS slices

      DTFE Velocity Field analysis

      Voronoi Foam Scaling

       Void Hierarchy:     I.    Excursion set formulation

                                          II.    Evolving void hierarchy

      the Cosmic Foam and Tides

      Tracing Tidal Influence through optimized Least Action Principle

      Constrained Random Fields

      Cold Cosmic Flows

Scientific Focus: the Cosmic Foam

Over the past two decades we have witnessed a paradigm shift in our perception of the Megaparsec scale structure in the Universe. As increasingly elaborate galaxy redshift surveys charted ever larger regions in the nearby cosmos, an intriguingly complex and salient

the Cosmic Foam

cosmic foamlike network appeared to permeate the observable Universe and has established itself as a quintessential characteristic of the cosmic matter and galaxy distribution. In addition, elaborate efforts have enabled us to study the migration streams and dynamics involved in building up such structures. Meanwhile, the primordial circumstances out of which these patterns and objects have been evolving have been revealed by an array of Cosmic Microwave Background experiments. Their detailed view of the pristine Universe has revolutionized cosmology. Meanwhile, the intermediate eons of a youthful Universe have gradually been disclosing ever more secrets as large telescopes, sensitive instruments and sophisticated detectors have been leading the exploration of the high redshift Universe. Step by step the various pieces of information -- yielded by radio, infrared, optical and up to X-ray and gamma-ray frequency observations -- are assembling into a highly versatile and elaborate picture of the evolution of our Cosmos. Within this extensive context, the Megaparsec Universe has been functioning as a bedrock on which a strong basic model and scenario of structure formation has been founded, based upon the gravitational instability of the primordial matter distribution.

the Voronoi Foam Model