Particle, Fields, Relativistic Astrophysics, and General Relativity

This program investigates the fundamental physics of ultra-dense matter, compact stellar objects, and the early universe, with particular emphasis on the theoretical modeling of pulsars, proto-neutron stars, quark stars, and related extreme astrophysical environments. It aims to understand how matter behaves at densities far beyond those found in atomic nuclei, exploring the transition from hadronic matter to deconfined quark matter. These studies are crucial for interpreting observable features of compact stars, including mass-radius relations, spin-down evolution, neutrino cooling, and possible signals from exotic objects like quark stars.

A major focus of the program is the exploration of alternative frameworks to Einstein’s general relativity, including pseudo-complex gravity, which extends spacetime geometry to avoid singularities and introduces dynamic cosmological behavior. These models are especially relevant in regimes where classical general relativity is expected to break down, and they serve as a gateway to understanding phenomena that may arise in the context of quantum gravity. Connections to ideas from string theory and holography, such as the AdS/CFT correspondence, are actively explored to bridge the gap between gravitational theory and quantum field dynamics.

The program also addresses the theoretical prediction of relic gravitational waves generated during the universe’s earliest phases, particularly in scenarios involving non-standard inflation, noncommutative geometry, and foliated spacetime structures. These gravitational wave backgrounds could offer unique observational windows into physics near the Planck scale, where quantum gravity effects become significant.

In addition, the thermodynamics of scalar and vector bosons is studied in hot and dense conditions, relevant not only for proto-neutron stars but also for matter created in heavy-ion collisions. Using tools such as relativistic mean-field theory and effective field models like the NJL model, this program provides students with an interdisciplinary and rigorous foundation in nuclear astrophysics, particle physics, and the search for a unified description of matter and gravity.


Key Research Themes


Compact Stars and Quark Matter

  • Equation of state (EOS) modeling at supranuclear densities
  • Phase transitions from hadronic to quark matter
  • Hybrid stars and the role of color superconductivity
  • Structure and evolution of pulsars
  • Rotational stellar instabilities and gravitational radiation
  • Super-strong magnetic fields
  • White dwarfs


General Relativity

  • Compact star modeling
  • Relativistic cosmology
  • Black hole structure and dynamics
  • Gravitational wave spectra from non-standard inflationary models
  • Non-commutative geometry and quantum spacetime foliations
  • Interface between quantum gravity candidates and observational cosmology


Finite-Temperature Field Theory in Dense Matter

  • Thermodynamics of ultra-hot hadronic matter
  • Applications to proto-neutron stars
  • Relativistic quantum field theory


Student Involvement


Students gain rigorous training in:

  • Relativistic many-body theory and quantum field theory
  • Numerical modeling of stellar structure (TOV equations, EOS solvers)
  • General relativity (including modified theories like pc-GR)
  • Symbolic and numerical computation using tools such as Mathematica and modern Fortran


Research students are encouraged to:

  • Present at national and international conferences
  • Co-author publications in peer-reviewed journals
  • Pursue interdisciplinary perspectives that include philosophy of science


Recent and Ongoing Projects

  • Pseudo-Complex Gravity and Dynamical Cosmological Constant Transitions
  • Relic Gravitational Waves in Noncommutative Foliated Spacetime
  • Thermal Bosons in Hot and Dense Nuclear Matter
  • Quantum Structures and Non-Singular Black Hole Models

For more information, contact Professor Fridolin Weber, fweber@sdsu.edu