115 citations · 317 across the 7 of their papers we have counts for
7 papers
When action is not least for systems with action-dependent Lagrangians
Joseph Ryan
The dynamics of some non-conservative and dissipative systems can be derived by calculating the first variation of an action-dependent action, according to the variational principl…
Cosmological constraints from HII starburst galaxy, quasar angular size, and other measurements
Shulei Cao, Joseph Ryan, Bharat Ratra
We compare the constraints from two (2019 and 2021) compilations of HII starburst galaxy (HIIG) data and test the model-independence of quasar angular size (QSO) data using six spa…
Observational constraints on the cosmological expansion rate and spatial curvature
Joseph Ryan
Observations conducted over the last few decades show that the expansion of the Universe is accelerating. In the standard model of cosmology, this accelerated expansion is attribut…
Cosmological constraints from HII starburst galaxy apparent magnitude and other cosmological measurements
Shulei Cao, Joseph Ryan, Bharat Ratra
We use HII starburst galaxy apparent magnitude measurements to constrain cosmological parameters in six cosmological models. A joint analysis of HII galaxy, quasar angular size, ba…
Evidence against Ryskin's model of cosmic acceleration
Joseph Ryan
In this paper I examine how well Ryskin's model of emergent cosmic acceleration fits several sets of cosmological observations. I find that while Ryskin's model is somewhat compati…
Baryon acoustic oscillation, Hubble parameter, and angular size measurement constraints on the Hubble constant, dark energy dynamics, and spatial curvature
Joseph Ryan, Yun Chen, Bharat Ratra
In this paper we use all available baryon acoustic oscillation, Hubble parameter, and quasar angular size data to constrain six dark energy cosmological models, both spatially flat…