arXiv subjects

Vincent R. Siggia

Publications and source records attributed to Vincent R. Siggia.

3 recordsLinked to original sources

arXiv2026

Comparison of $f(R,T)$ Gravity with Multiple Datasets

We examine $f(R,T)=R+λT^ε$ gravity models by finding the best fit parameters for various values of $ε$. This is accomplished by analyzing data from the cosmic microwave background, baryon acoustic oscillation observations, cosmic chronometer, and Type Ia supernovae introducing correlations and radiation effects to our previous work. We find the probability distribution for the best fit model around the value of $ε=0.010^{+0.013}_{-0.021}$, consistent with the standard cosmological model value of $ε= 0$.

gr-qc↗

arXiv2026

Exploration of Parameters in f(R,T) Gravity and Comparison with Type Ia Supernovae Data

The expansion of the Universe in $f(R,T)$ gravity is studied. We consider functions of the form $f(R,T)=R+λT^ε$ where $ε<1$. We find that for all models with $ε<0$, the Universe transitions to exponential growth at late times, just as it does in the standard cosmological model, which corresponds to $ε=0$. It also fits the type Ia supernova data slightly better than the standard cosmological model, without increasing the number of parameters of the theory. In contrast, the fits for $ε>0$ rapidly become worse than the standard cosmological model.

gr-qc↗

arXiv2025

Comparison of $f(R,T)$ Gravity with Type Ia Supernovae Data

The expansion of the universe in $f(R,T)$ gravity is studied. By focusing on functions of the form $f(R,T)=f_1(R)+f_2(T)$, we assert that present day acceleration can be achieved if the functional form of $f_2(T)$ either grows slowly or falls as a function of $T$. In particular, we demonstrate that when $f_2(T) \propto T^{-1}$, the universe transitions to exponential growth at late times, just as it does in the standard cosmological model. A comparison of predictions of this model, with Type Ia supernovae shows that this model fits the data as well or even slightly better than the standard cosmological model without increasing the number of parameters.

gr-qc↗