The Minkowski limit of pure R² gravity is reinterpreted as a thermal singularity via scalar-tensor to Eckart fluid analogy, showing infinite departure from GR rather than recovery.
Gravitational Wave Polarization Modes in $f(R)$ Theories
1 Pith paper cite this work. Polarity classification is still indexing.
1
Pith paper citing it
abstract
Many studies have been carried out in the literature to evaluate the number of polarization modes of gravitational waves in modified theories, in particular in $f(R)$ theories. In the latter ones, besides the usual two transverse-traceless tensor modes present in general relativity, there are two additional scalar ones: a massive longitudinal mode and a massless transverse mode (the so-called breathing mode). This last mode has often been overlooked in the literature, due to the assumption that the application of the Lorenz gauge implies transverse-traceless wave solutions. We however show that this is in general not possible and, in particular, that the traceless condition cannot be imposed due to the fact that we no longer have a Minkowski background metric. Our findings are in agreement with the results found using the Newman-Penrose formalism, and thus clarify the inconsistencies found so far in the literature.
fields
gr-qc 1years
2026 1verdicts
UNVERDICTED 1representative citing papers
citing papers explorer
-
New interpretation of the Minkowski limit of $R^2$ gravity
The Minkowski limit of pure R² gravity is reinterpreted as a thermal singularity via scalar-tensor to Eckart fluid analogy, showing infinite departure from GR rather than recovery.