Kostas Kokkotas

Research Interests



Pulsating Relativistic Stars

In collaboration with Bernard Schutz (Cardiff) and more recently with Nils Andersson (Cardiff) and Yasufumi Kojima (Hiroshima) we have studied the Quasi-Normal Modes of Pulsating Relativistic Stars. Two quite interesting results are the following:
  • We have found a new family of normal mode frequencies the w-modes which are mainly modes of the spacetime and not of the fluid. These modes have no analog in Newtonian theory.
  • We have proven the existence of Axial Modes for normal stars, and we have shown that they are practically spacetime modes.
  • In collaboration with Gerhard Schaefer (Jena) we study the PN stellar oscillations.

    Coalescing Binaries

  • In collaboration with Gerhard Schaefer (Jena) we have studied the effects of tides and of tidal resonances in the evolution of close binary systems. This work continues in the direction of using higher PN terms in the desctription of binary evolution.
  • In collaboration with Nicolas Spyrou (Thessaloniki) we have studied the influence of internal characteristics of the stars in the evolution of the binary systems and the energy loss.

    Gravitational Wave Data Analysis

    In collaboration with Andrzej Krolak (Warsaw), George Tsegas (Thessaloniki), Gerhard Schaefer (Jena) and later Piotr Jaranowski (Bialystock) we have studied and continue the research on the statistical analysis of the estimatiors of the Newtonian and post-Newtonian parameters of the gravitational wave signal from a coalescing binary from one or a network of detectors.

    Quantum Groups

    In collaboration with Dennis Bonatsos (Athens) and Costas Daskaloyannis (Thessaloniki) we have studied:
  • The WKB equivalent potentials for q-deformed harmonic and anharmonic oscillators.
  • Deformed Oscillator Algebras for 2-dimensional quantum superintegrable systems