Test of Hybrid Metric-Palatini f(R)-Gravity in Binary Pulsars

Beyond Horndeski interactions induced by quantum effects

“…Such interactions appear at least at 2PN (post-Newtonian) order or higher [43,44]. Although such effects can be calculated [45,46,47,48,49,11], it would be challenging to efficiently constraint them with the current empirical data.…”

Relativistic perihelion shift of Mercury revisited

“…However, it is interesting that Einstein used a similar notation as Gerber (1898), namely, the angle ϕ from Figure 3 satisfies ϕ = Φ/2, where Φ appears in Gerber's formula (9). Remark Although Formula (1) was derived for a massless test particle representing Mercury, it is often applied to close binaries whose components have positive masses M 1 and M 2 (see, e.g., Avdeev et al 2020; Bowler 2010; Guinan & Maloney 1985; Hilditch 2001; Stovall et al 2018; Susobhanan et al 2018; Weisberg & Taylor 2005). Note that PSR J0737–3039 is the only known double pulsar.…”

“…Remark 10. Although Formula (1) was derived for a massless test particle representing Mercury, it is often applied to close binaries whose components have positive masses M 1 and M 2 (see, e.g., Avdeev et al 2020;Bowler 2010;Guinan & Maloney 1985;Hilditch 2001;Stovall et al 2018;Susobhanan et al 2018;Weisberg & Taylor 2005). Note that PSR J0737-3039 is the only known double pulsar.…”

Polarization and speed of gravitational waves in hybrid metric-Palatini f(R)-gravity

“…The hybrid f(R)-theory was tested using a parameterized post-Keplerian formalism. As a result, it was shown that hybrid f(R)-gravity predicts a wider range of possible masses for the components of binary pulsars in comparison with GR [24].…”