9 papers
The de Sitter Scalar Discrete Series: Gupta-Bleuler Structure and Holography
Maryam Bajalan, Jean-Pierre Gazeau, Hamed Pejhan
We show that scalar discrete-series unitary irreducible representations (UIRs) () of the de Sitter (dS) group admit a dS-covariant Kre…
Infrared Spectral Gap in a Gluonic Dark Sector and the Galactic Acceleration Scale
Gilles Cohen-Tannoudji, Jean-Pierre Gazeau, Hamed Pejhan +1
We further develop a trace-anomaly-motivated gluonic scenario in which cold dark matter (CDM) is modeled as a long-lived color-singlet Bose-Einstein condensate seeded at the QCD co…
Massless Representations in Conformal Space and Their de Sitter Restrictions
Jean-Pierre Gazeau, Hamed Pejhan, Ivan Todorov
The monograph offers a coherent and self-contained treatment of massless (ladder) representations of the conformal group U(2,2) and their restriction to the de Sitter group Sp(2,2)…
A unified framework for graviton, "partially massless" graviton, and photon fields in de Sitter spacetime under conformal symmetry
Jean-Pierre Gazeau, Hamed Pejhan
We develop a conformally invariant (CI) framework in -dimensional de Sitter (dS) spacetime, that unifies the descriptions of graviton, ``partially massless'' graviton, and p…
Holomorphic Discrete Series of SU(1,1): Orthogonality Relations, Character Formulas, and Multiplicities in Tensor Product Decompositions
Jean-Pierre Gazeau, Mariano A. del Olmo, Hamed Pejhan
The SU group plays a fundamental role in various areas of physics, including quantum mechanics, quantum optics, and representation theory. In this work we revisit the holomo…
A misleading naming convention: de Sitter `tachyonic' scalar fields
Jean-Pierre Gazeau, Hamed Pejhan
We revisit the concept of de Sitter (dS) 'tachyonic' scalar fields, characterized by discrete negative squared mass values, and assess their physical significance through a rigorou…