Table 5 - uploaded by Christina Kreisch
Content may be subject to copyright.
Source publication
The discovery of the electromagnetic counterpart to GW170817 severely constrains the tensor mode propagation speed, eliminating a large model space of Horndeski theory. We use the cosmic microwave background data from Planck and the joint analysis of the BICEP2/Keck Array and Planck, galaxy clustering data from the SDSS LRG survey, BOSS baryon acou...
Context in source publication
Context 1
... principle, the Bayes factor should be used to com- pare the models and the AIC proves only an approximation to it [see, e.g., the introduction of 33, for the Bayes factor]. In Table 5 we list the individual ∆AIC values for each data set used in the CMB and CMB+LSS combinations, as well as the total ∆AIC value for both combinations. All ∆AIC values are positive, indicating the α B = 0 model is preferred for all data sets. ...
Similar publications
Recent analyses of the cosmic microwave background (CMB) and the Lyman-alpha forest indicate a mild preference for a deviation from a power law primordial matter power spectrum (a so-called negative `running'). We use an extension to the BAHAMAS suite of cosmological hydrodynamic simulations to explore the effects that a running scalar spectral ind...
The presence of massive neutrinos affects structure formation, leaving imprints on large-scale structure observables such as the weak lensing field. The common lensing analyses with two-point statistics are insensitive to the large amount of non-Gaussian information in the density field. We investigate non-Gaussian tools, in particular the Minkowsk...
Citations
... f (R) gravity [14], quintessence [15,16], Brans-Dicke models [17], kinetic braiding [18], Galileons/generalised Galileons [19][20][21]). In this paper, we will focus on models of this class, where four functions of time fully describe the perturbations [3,6,8]: the kineticity α K , the braiding α B , the Planck-mass run rate α M and the tensor speed excess α T . 2 Observational as well as theoretical constraints have been put on these free functions, combining the Cosmic Microwave Background (CMB), large-scale structure data and gravitational-wave detections [27][28][29][30][31][32][33][34][35][36][37]. However, at the moment only the parameter α T is tightly restricted to its GR value of zero by the gravitational-wave event GW170817 and its electromagnetic counterpart, GRB170817A [38]. ...
Upcoming galaxy surveys provide the necessary sensitivity to measure gravitational redshift, a general relativistic effect that generates a dipole in galaxy clustering data when correlating two distinct populations of galaxies. Here, we study the constraining power of gravitational redshift within the framework of the effective theory of interacting dark energy. This formalism describes linear cosmological perturbations in scalar-tensor theories of gravity with a limited number of free functions, and allows each particle species to be coupled differently to the gravitational sector. In this work, we focus on Horndeski theories with a non-minimal coupling of dark matter to the scalar degree of freedom, yielding a breaking of the weak equivalence principle for this cosmic component, a scenario that is yet untested. We show that the dipole generated by gravitational redshift significantly breaks degeneracies and tightens the constraints on the parameters of the effective theory compared to the standard redshift-space distortion analysis solely based on the even multipoles in the galaxy correlation function, with an improvement of up to ∼ 50% for populations with a galaxy bias difference equal to 1. We make the Python package EF-TIGRE (Effective Field Theory of Interacting dark energy with Gravitational REdshift) developed for this work publicly available (https://github.com/Mik3M4n/EF-TIGRE).
... Similar to general relativity, Horndeski's theory possesses the same diffeomorphism invariance and second-order field equations. Given the superiority of the Horndeski theory in explaining the accelerated expansion of the universe [58,59], this theory and its BH solutions have attracted a great deal of attention in the scientific community [60][61][62][63][64][65][66]. In particular, the authors of [67] presented a static, spherically symmetric BH solution in Horndeski gravity. ...
Research on the observational appearance of black holes, both in general relativity and modified gravity, has been in full swing since the Event Horizon Telescope Collaboration announced photos of M87* and Sagittarius A*. Nevertheless, limited attention has been given to the impact of tilted accretion disks on black hole images. This paper investigates the 230 GHz images of non-rotating hairy black holes illuminated by tilted, thin accretion disks in Horndeski gravity with the aid of a ray tracing method. The results indicate that reducing the scalar hair parameter effectively diminishes image luminosity and extends both the critical curve and the inner shadow. This trend facilitates the differentiation between hairy black holes and Schwarzschild black holes, especially in certain parameter spaces where the current Event Horizon Telescope array is capable of capturing such variations. Furthermore, we observe that the inclination of the tilted accretion disk can mimic the observation angle, consequently affecting image brightness and the morphology of the inner shadow. In specific parameter spaces, alterations in the tilt or position of the accretion disk can lead to a drift in the light spot within the images of hairy black holes. This finding may establish a potential correlation between the precession of the tilted accretion disk and image features. Additionally, through an examination of images depicting hairy black holes surrounded by two thin accretion disks, we report the obscuring effect of the accretion environment on the inner shadow of the black hole.
... However, Refs. [22][23][24] pointed out that the observation of the speed of tensor gravitational waves in the Universe by the gravitational wave event GW170817 together with the gamma ray burst GRB170817A would severely constrain the possible parameter space of metric Horndeski theory. Specifically, GW170817 and GRB170817A require the tensor gravitational wave speed c g to meet [25,26] ...
... By substituting Eq. (24) into Eq. (23), and using the linearity of Eq. (23), we obtain the following equation: ...
In this paper, we investigate the possible parameter space of Palatini–Horndeski theory with gravitational waves in a spatially flat Universe. We develop a general method for obtaining the speed of gravitational waves in the Palatini formalism in the cosmological background and we find that if the theory satisfies the following condition: in any spatially flat cosmological background, the tensor gravitational wave speed is the speed of light c , then only $$S = \int d^4x \sqrt{-g} \big [K(\phi ,X)-G_{3}(\phi ,X){{\tilde{\Box }}}\phi +G_{4}(\phi ){\tilde{R}}\big ]$$ S = ∫ d 4 x - g [ K ( ϕ , X ) - G 3 ( ϕ , X ) □ ~ ϕ + G 4 ( ϕ ) R ~ ] is left as the possible action in Palatini–Horndeski theory. We also find that when $$G_{5}(\phi ,X)\ne 0$$ G 5 ( ϕ , X ) ≠ 0 , the tensor part of the connection will propagate and there are two different tensor gravitational wave speeds.
... Furthermore, the KGB model trivially allows gravitational waves to propagate at the speed of light [18], which is in agreement with the recent observation of the GW170817 event [20]. In addition, the parameter-space of the theory has also been confronted with cosmological observables [21][22][23][24][25], rendering this set-up as a viable DE model. Nevertheless, note that some specific subclasses of the KGB theory may be found at tension with cosmological data (see, for example, the discussion on Cubic Galilean gravity in references [26][27][28]). ...
We revise the expansion history of the scalar field theories known as Kinetic Gravity Braiding. These theories are well-known for the possibility of driving the expansion of the cosmos towards a future self-tuning de Sitter state when the corresponding Lagrangian is invariant under constant shifts in the scalar field. Nevertheless, this is not the only possible future fate of these shift-symmetric models. Using a dynamical system formulation we show that future cosmological singularities can also appear in this framework. Moreover, we present explicit examples where the future attractor in the configuration space of the theory corresponds to a big rip singularity.
... However, even if gravity is modified to cure a particular aspect of GR, discrepancies may arise in any other aspects of it. For example, the measurement of the speed of gravitational wave from GW170817 multimessenger observations tightly restricts the value of a T in Horndeski family [6], eliminating a number of theories with exciting features within this family. The above example indicates that applying simultaneous observational constraints with high precision yields tighter bounds on theo-retical parameters. ...
Tests have to be performed to rule out proposals for gravity modification. We propose a new idea for constraining alternative theories of gravity using temperature-dependent white dwarf (WD) mass-radius (MR) observational data. We have shown that several alternatives to general relativity (GR), which modified GR only within matter, might be reduced to the well-known Poisson equation similar to that of Eddington-inspired Born Infeld (EiBI) and Minimal Exponential Measure (MEMe) gravity. Retaining EiBI notation, we constrain the value of the coupling constant, $$\kappa $$ κ , using a high-precision model-independent measurement of WD MR observations. We have demonstrated that the WD model should include detailed physics to achieve good precision. The model should include their temperature and evolutionary aspects, which may be computationally expensive. To overcome this issue, we construct a semi-analytical surrogate model based on Mestel’s model, calibrated with tabulated, detailed realistic models, to correct the zero-temperature radius. We have shown that the best-fit value of $$\kappa $$ κ depends on the WD model, with the ’thick’ envelope models more consistent in describing data. The tightest bound obtained from the most precise MR measurement, QS Vir, with $$-0.19$$ - 0.19 $$\lesssim \kappa \lesssim $$ ≲ κ ≲ 0.22 in $$10^3$$ 10 3 m $$^5$$ 5 kg $$^{-1}$$ - 1 s $$^{-2}$$ - 2 for $$2\sigma $$ 2 σ $$(\sim 95\%)$$ ( ∼ 95 % ) credibility. Overall, we assert that the recent precise WD MR measurements, combined with our current understanding of WD structure, are insufficient to see the deviation from the one predicted by GR. Both more precise observation data and detailed WD modelling are required to rule out gravity modification.
... (2.6) Certain analyses, e.g. [42][43][44], fix γ MG 3 (a) = 0 to enforce that the speed of the propagation of gravitational waves (GW) be equal to the speed of light. This requirement is motivated by the constraints derived from the binary neutron-star merger events "observed" by both GW and optical instruments (see [45] for a review), e.g. ...
... where c 2 T and c 2 are the squared speeds of GW and of light, respectively. Here α T (a) quantifies the GW speed's deviation from the speed of light, and can be mapped into the γ MG 3 function as [42] ...
We propose and numerically validate a new fitting formula that is sufficiently accurate to model the growth of structure in Horndeski theories of modified gravity for upcoming Stage IV and V large-scale structure surveys. Based on an analysis of more than 18,000 Horndeski models and adopting the popular parameterization of the growth rate $f(z) = \Omega_{M}(z)^{\gamma}$, we generalize the constant growth index $\gamma$ to a two-parameter redshift-dependent quantity, $\gamma(z)$, that more accurately fits these models. We demonstrate that the functional form $\gamma(z)=\gamma_0+\gamma_1z^2 / (1+z)$ improves the median $\chi^2$ of the fit to viable Horndeski models by a factor of $\sim40$ relative to that of a constant $\gamma$, and is sufficient to obtain unbiased results even for precise measurements expected in Stage IV and V surveys. Finally, we constrain the parameters of the new fitting formula using current cosmological data.
... Any constraints placed on the general Horndeski framework can be rapidly translated into statements about individual members of the Horndeski class. As such, constraining Horndeski gravity has emerged over the past ten years as an efficient and relatively agnostic approach for performing tests of gravity with new data [44][45][46][47][48][49][50][51][52][53][54][55]. At the level of linear perturbation theory, the popular parameterisation developed by [56], sometimes known as the effective field theory of dark energy (EFTofDE), has been successfully constrained by a variety of observations, including the binary neutron star merger GW170817 [57][58][59][60][61][62]. ...
We introduce Hi-COLA , a code designed to run fast, approximate N -body simulations of non-linear structure formation in reduced Horndeski gravity. Given an input Lagrangian, Hi-COLA dynamically constructs the appropriate field equations and consistently solves for the cosmological background, linear growth, and screened fifth force of that theory. Hence Hi-COLA is a general, adaptable, and useful tool that allows the mildly non-linear regime of many Horndeski theories to be investigated for the first time, at low computational cost. In this work, we first describe the screening approximations and simulation setup of Hi-COLA for theories with Vainshtein screening. We validate the code against traditional N -body simulations for cubic Galileon gravity, finding 2.5% agreement up to k max = 1.2 h /Mpc. To demonstrate the flexibility of Hi-COLA , we additionally run the first simulations of an extended shift-symmetric gravity theory. We use the consistency and modularity of Hi-COLA to dissect how the modified background, linear growth, and screened fifth force all contribute to departures from ΛCDM in the non-linear matter power spectrum. Hi-COLA can be found at https://github.com/Hi-COLACode/Hi-COLA .
... However, studies using cosmological data to constrain DHOST theories are still limited (Hirano et al. 2019a;Traykova et al. 2019;Peirone et al. 2019;Hiramatsu 2022). On the other hand, many papers on Horndeski theories have used cosmological data to constrain the model (Okada et al. 2013; Barreira et al. 2014;Bellini et al. 2016;Mueller et al. 2018;Kreisch & Komatsu 2018;Arai & Nishizawa 2018;Noller & Nicola 2020Raveri 2020;Melville & Noller 2020;Perenon et al. 2019;Noller 2020). Therefore, exploring new cosmological methods for constraining DHOST theories is of great significance. ...
We report a new test of modified gravity theories using the large-scale structure of the Universe. This paper is the first attempt to (1) apply a joint analysis of the anisotropic components of galaxy two- and three-point correlation functions (2 and 3PCFs) to actual galaxy data and (2) constrain the nonlinear effects of degenerate higher-order scalar-tensor (DHOST) theories on cosmological scales. Applying this analysis to the Baryon Oscillation Spectroscopic Survey (BOSS) data release 12, we obtain the lower bounds of $-1.655 < \xi_{\rm t}$ and $-0.504 < \xi_{\rm s}$ at the $95\%$ confidence level on the parameters characterising the time evolution of the tidal and shift terms of the second-order velocity field. These constraints are consistent with GR predictions of $\xi_{\rm t}=15/1144$ and $\xi_{\rm s}=0$. Moreover, they represent a $35$-fold and $20$-fold improvement, respectively, over the joint analysis with only the isotropic 3PCF. We ensure the validity of our results by investigating various quantities, including theoretical models of the 3PCF, window function corrections, cumulative ${\rm S/N}$, Fisher matrices, and statistical scattering effects of mock simulation data. We also find statistically significant discrepancies between the BOSS data and the Patchy mocks for the 3PCF measurement. Finally, we package all of our 3PCF analysis codes under the name \textsc{HITOMI} and make them publicly available so that readers can reproduce all the results of this paper and easily apply them to ongoing future galaxy surveys.
... We showed that for both profiles considered in this work, the reconstructions are able to detect the deviations from GR at 2σ in the redshift range 0.5 z 1.5 where DESI's (RSD) constraining power lies. The inclusion of external data sets, such as the (modified) luminosity distance of gravitational waves d GW L (z) [62] or the Integrated Sachs-Wolfe effect (ISW) seen in the temperature anisotropies of the Cosmic Microwave Background (CMB) in cross-correlation with LSS surveys would provide interesting (model-independent) constraints on the allowed deviations from GR [63]. Moreover, we note that the effect of massive neutrinos would be tracked more accurately if we allow for a scale-dependent growth. ...
Based on a formalism introduced in our previous work, we reconstruct the phenomenological function $G_{\rm eff}(z)$ describing deviations from General Relativity (GR) in a model-independent manner. In this alternative approach, we model $\mu\equiv G_\mathrm{eff}/G$ as a Gaussian process and use forecasted growth-rate measurements from a stage-IV survey to reconstruct its shape for two different toy-models. We follow a two-step procedure: (i) we first reconstruct the background expansion history from Supernovae (SNe) and Baryon Acoustic Oscillation (BAO) measurements; (ii) we then use it to obtain the growth history $f\sigma_8$, that we fit to redshift-space distortions (RSD) measurements to reconstruct $G_\mathrm{eff}$. We find that upcoming surveys such as the Dark Energy Spectroscopic Instrument (DESI) might be capable of detecting deviations from GR, provided the dark energy behavior is accurately determined. We might even be able to constrain the transition redshift from $G\to G_\mathrm{eff}$ for some particular models. We further assess the impact of massive neutrinos on the reconstructions of $G_\mathrm{eff}$ (or $\mu$) assuming the expansion history is given, and only the neutrino mass is free to vary. Given the tight constraints on the neutrino mass, and for the profiles we considered in this work, we recover numerically that the effect of such massive neutrinos do not alter our conclusions. Finally, we stress that incorrectly assuming a $\Lambda$CDM expansion history leads to a degraded reconstruction of $\mu$, and/or a non-negligible bias in the ($\Omega_\mathrm{m0}$,$\sigma_{8,0}$)-plane.
... However, Refs. [22][23][24] pointed out that the observation of the speed of tensor gravitational waves in the Universe by the gravitational wave event GW170817 together with the gamma ray burst GRB170817A would severely constrain the possible parameter space of metric Horndeski theory. Specifically, GW170817 and GRB170817A require the tensor gravitational wave speed c g to meet [25,26] ...
In this paper, we investigate the possible parameter space of Palatini-Horndeski theory with gravitational waves in a spatially flat Universe. We find that if the theory satisfies the following condition: in any spatially flat cosmological background, the tensor gravitational wave speed is the speed of light $c$, then only $S = \int d^4x \sqrt{-g} \big[K(\phi,X)-G_{3}(\phi,X){\tilde{\Box}}\phi+G_{4}(\phi)\tilde{R}\big]$ is left as the possible action in Palatini-Horndeski theory.
