LCDM Research Articles

Galaxy clustering in modified gravity from full-physics simulations – I. Two-point correlation functions

ABSTRACT We present an in-depth investigation of galaxy clustering based on a new suite of realistic large-box galaxy formation simulations in $f(R)$ gravity, with a subgrid physics model that has been recalibrated to reproduce various observed stellar and gas properties. We focus on the two-point correlation functions of the luminous red galaxies (LRGs) and emission line galaxies (ELGs), which are primary targets of ongoing and future galaxy surveys such as Dark Energy Spectroscopic Instrument (DESI). One surprising result is that, due to several non-trivial effects of modified gravity on matter clustering and the galaxy–halo connection, the clustering signal does not depend monotonically on the fifth-force strength. For LRGs, this complicated behaviour poses a challenge to meaningfully constraining this model. For ELGs, in contrast, this can be straightforwardly explained by the time evolution of the fifth force, which means that weaker $f(R)$ models can display nearly the same – up to 25 per cent – deviations from Lambda cold dark matter model as the strongest ones, albeit at lower redshifts. This implies that even very weak $f(R)$ models can be strongly constrained, unlike with most other observations. Our results show that galaxy formation acquires a significant environment dependence in $f(R)$ gravity, which, if not properly accounted for, may lead to biased constraints on the model. This highlights the essential role of hydrodynamical simulations in future tests of gravity exploring precision galaxy-clustering data from the likes of DESI and Euclid.

Dwarf galaxies as a probe of a primordially magnetized Universe

Aims. The true nature of primordial magnetic fields (PMFs) and their role in the formation of galaxies remains elusive. To shed light on these unknowns, we investigated their impact by varying two sets of properties: (i) accounting for the effect of PMFs on the initial matter power spectrum and (ii) accounting for their magneto-hydrodynamical effects on the formation of galaxies. By comparing both, we can determine the dominant agent in shaping galaxy evolution. Methods. We used the magneto-hydrodynamics code RAMSES to generate multiple new zoom-in simulations for eight different host halos of dwarf galaxies across a wide luminosity range of 103 − 106 L⊙. These halos were selected from a ΛCDM cosmological box, tracking their evolution down to redshift z = 0. We explored a variety of primordial magnetic field (comoving) strengths of Bλ ranging from 0.05 to 0.50 nG. Results. We find that magnetic fields in the interstellar medium not only modify star formation processes in dwarf spheroidal galaxies, but these fields also entirely prevent the formation of stars in less compact, ultra-faint galaxies with halo masses and stellar masses below, respectively, ∼2.5 × 109 and 3 × 106 M⊙. At high redshifts, the impact of PMFs on host halos of dwarf galaxies through the modification of the matter power spectrum is more dominant than the influence of magneto-hydrodynamics in shaping their gaseous structure. Through the amplification of small perturbations ranging in mass from 107 to 109 M⊙ in the ΛCDM+PMFs matter power spectrum, primordial fields expedite the formation of the first dark matter halos, leading to an earlier onset and a higher star formation rate at redshifts of z > 9. We investigated the evolution of various energy components and demonstrated that magnetic fields with an initial strength of Bλ ≥ 0.05 nG exhibit a strong growth of magnetic energy, accompanied by a saturation phase that begins soon after the growth phase. These trends persist consistently, regardless of the initial conditions or whether it is the classical ΛCDM model or ΛCDM modified by PMFs. Lastly, we investigated the impact of PMFs on the present-time observable properties of dwarf galaxies, namely: the half light radius, V-band luminosity, mean metallicity, and velocity dispersion profile. We find that PMFs with moderate strengths of Bλ ≤ 0.10 nG show an impressive agreement with the scaling relations of the observed Local Group dwarfs. However, stronger fields lead to larger sizes and higher velocity dispersions.

Model-independent cosmographic constraints from DESI 2024

Context. We explore model-independent constraints on the Universe kinematics up to the snap and jerk hierarchical terms, considering the latest baryon acoustic oscillation (BAO) release provided by the DESI collaboration. Aims. We intend to place novel and more stringent constraints on the cosmographic series, incorporating three combinations of data catalogs: the first made by BAO and observational cosmic chronometers, the second made by BAO and type Ia supernovae, and the last including all the cited data sets. Methods. Considering the latest BAO data provided by the DESI collaboration and tackling the rd parameter to span within the range [144,152] Mpc, with a fixed step of δrd = 2 Mpc, we employed Monte Carlo Markov chain analyses based on the Metropolis algorithm to fix novel bounds on the cosmographic series, fixing the deceleration, q0 , the jerk, j0 , and the snap, s0, parameters, up to the 2σ level. A comparison between the results of the Planck satellite with those obtained by the DESI collaboration is also reported. Results. Our findings showcase a significant departure in terms of j0 even at the 1σ confidence level, albeit compatible with the ACDM paradigm in regard to q0 and s0 at the 2σ level. Analogously, the h0 tension appears alleviated in the second hierarchy when including snap. Conclusions. Our method excludes models that significantly depart from the standard cosmological model. Particularly, direct comparisons with the ACDM and wCDM models and the Chevallier-Polarski-Linder parameterisation are explored, which definitively favour the wCDM scenario over other approaches, contradicting the findings of the original DESI collaboration.

Dark Age Consistency in the 21cm Global Signal.

We propose a new observable for the 21cm global signal during the dark ages, "the dark age consistency ratio," which could serve as a critical test of models beyond the standard Λ cold dark matter (ΛCDM) model, particularly in future missions using a telescope on the moon or satellite orbiting around the moon. The new observable is motivated from the fact that the shape of the functional form of the 21cm signal against the frequency is almost cosmological-parameter independent in the ΛCDM. The dark age consistency ratio takes a certain definite value in the ΛCDM case, which enables us to easily falsify models beyond the standard model motivated by some particle physics and gravity theories. The new observable just needs measurements of the brightness temperature at a few frequency bands during the dark ages, and thus it allows us to test cosmological scenarios even with limited information on the 21cm global signal at the early stage of future lunar missions.

MUSE adaptive-optics spectroscopy confirms dual active galactic nuclei and strongly lensed systems at sub-arcsec separation

The novel Gaia multi peak (GMP) technique has proven to be able to successfully select dual and lensed active galactic nuclei (AGN) candidates at sub-arcsecond separations. Both populations are important because dual AGN represent one of the central, still largely untested, predictions of ΛCDM cosmology, and compact lensed AGN allow us to probe the central regions of the lensing galaxies. In this work, we present high-spatial-resolution spectroscopy of 12 GMP-selected systems. We used the adaptive-optics assisted integral-field spectrograph MUSE at the VLT to resolve each system and investigate the nature of each component. All targets show the presence of two components confirming the GMP selection. We classify 4 targets as dual AGN, 3 as lensed quasar candidates, and 5 as a chance alignment of a star and an AGN. With separations ranging from 0.30″ to 0.86″, these dual and lensed systems are among the most compact systems discovered to date at z > 0.5. This is the largest sample of distant dual AGN with sub-arcsecond separations ever presented in a single paper.

Birth of Rapidly Spinning, Overmassive Black Holes in the Early Universe

The James Webb Space Telescope (JWST) has unveiled numerous massive black holes (BHs) in faint, broad-line active galactic nuclei (AGNs). The discovery highlights the presence of dust-reddened AGN populations, referred to as “little red dots (LRDs),” more abundant than X-ray-selected AGNs, which are less influenced by obscuration. This finding indicates that the cosmic growth rate of BHs within this population does not decrease but rather increases at higher redshifts beyond z ∼ 6. The BH accretion rate density deduced from their luminosity function is remarkably higher than that from other AGN surveys in X-ray and infrared bands. To align the cumulative mass density accreted to BHs with the observed BH mass density at z ≃ 4–5, as derived from the integration of the BH mass function, the radiative efficiency must be doubled from the canonical 10% value, achieving significance beyond the >3σ confidence level. This suggests the presence of rapid spins with 96% of the maximum limit among these BHs under the thin-disk approximation, maintained by prolonged mass accretion instead of chaotic accretion with randomly oriented inflows. Moreover, we derive an upper bound for the stellar mass of galaxies hosting these LRDs, ensuring consistency with galaxy formation in the standard cosmological model, where the host stellar mass is limited by the available baryonic reservoir. Our analysis gives a lower bound for the BH-to-galaxy mass ratio that exceeds the typical value known in the nearby universe and aligns with that for JWST-detected unobscured AGNs. Accordingly, we propose a hypothesis that the dense, dust-rich environments within LRDs facilitate the emergence of rapidly spinning and overmassive BH populations during the epoch of reionization. This scenario predicts a potential association between relativistic jets and other high-energy phenomena with overmassive BHs in the early universe.

The gravitational lensing imprints of DES Y3 superstructures on the CMB: a matched filtering approach

ABSTRACT Low-density cosmic voids gravitationally lens the cosmic microwave background (CMB), leaving a negative imprint on the CMB convergence $\kappa$. This effect provides insight into the distribution of matter within voids, and can also be used to study the growth of structure. We measure this lensing imprint by cross-correlating the Planck CMB lensing convergence map with voids identified in the Dark Energy Survey Year 3 (DES Y3) data set, covering approximately 4200 deg$^2$ of the sky. We use two distinct void-finding algorithms: a 2D void-finder that operates on the projected galaxy density field in thin redshift shells, and a new code, Voxel, which operates on the full 3D map of galaxy positions. We employ an optimal matched filtering method for cross-correlation, using the Marenostrum Institut de Ciències de l’Espai N-body simulation both to establish the template for the matched filter and to calibrate detection significances. Using the DES Y3 photometric luminous red galaxy sample, we measure $A_\kappa$, the amplitude of the observed lensing signal relative to the simulation template, obtaining $A_\kappa = 1.03 \pm 0.22$ ($4.6\sigma$ significance) for Voxel and $A_\kappa = 1.02 \pm 0.17$ ($5.9\sigma$ significance) for 2D voids, both consistent with Lambda cold dark matter expectations. We additionally invert the 2D void-finding process to identify superclusters in the projected density field, for which we measure $A_\kappa = 0.87 \pm 0.15$ ($5.9\sigma$ significance). The leading source of noise in our measurements is Planck noise, implying that data from the Atacama Cosmology Telescope, South Pole Telescope and CMB-S4 will increase sensitivity and allow for more precise measurements.

The TRGB-SBF Project. I. A Tip of the Red Giant Branch Distance to the Fornax Cluster with JWST

Differences between the local value of the Hubble constant measured via the distance ladder versus the value inferred from the cosmic microwave background with the assumption of the standard ΛCDM model have reached over 5σ significance. To determine if this discrepancy is due to new physics or more mundane systematic errors, it is essential to remove as many sources of systematic uncertainty as possible, by developing high-precision distance ladders that are independent of the traditional Cepheid and Type Ia supernova route. Here, we present JWST observations of three early-type Fornax Cluster galaxies, the first of 14 observations from a Cycle 2 JWST program. Our modest integration times allow us to measure highly precise tip of the red giant branch (TRGB) distances and they will also be used to perform measurements of surface brightness fluctuations (SBFs). From these three galaxies, we determine an average TRGB distance modulus to the Fornax Cluster of μ = 31.424 ± 0.077 mag or D = 19.3 ± 0.7 Mpc. With 11 more scheduled observations in nearby elliptical galaxies, our program will allow us to set the zero-point of the SBF scale to better than 2% for more distant measurements, charting a path toward a high-precision measurement of H 0 that is independent of the traditional Cepheid–supernova Ia distance ladder.

Euclid. I. Overview of the Euclid mission

The current standard model of cosmology successfully describes a variety of measurements, but the nature of its main ingredients, dark matter and dark energy, remains unknown. is a medium-class mission in the Cosmic Vision 2015--2025 programme of the European Space Agency (ESA) that will provide high-resolution optical imaging, as well as near-infrared imaging and spectroscopy, over about 14\,000\,deg$^2$ of extragalactic sky. In addition to accurate weak lensing and clustering measurements that probe structure formation over half of the age of the Universe, its primary probes for cosmology, these exquisite data will enable a wide range of science. This paper provides a high-level overview of the mission, summarising the survey characteristics, the various data-processing steps, and data products. We also highlight the main science objectives and expected performance.

Milky Way and Andromeda analogues from the TNG50 simulation

ABSTRACT We present the properties of Milky Way- and Andromeda-like (MW/M31-like) galaxies simulated within TNG50, the highest resolution run of the IllustrisTNG suite of lambda-cold dark matter magnetohydrodynamical simulations. We introduce our fiducial selection for MW/M31 analogues, which we propose for direct usage as well as for reference in future analyses. TNG50 contains 198 MW/M31 analogues, that is, galaxies with stellar discy morphology, with a stellar mass in the range of $M_* = 10^{10.5 - 11.2}~\rm {\rm M}_{\odot }$, and within an MW-like 500 kpc-scale environment at $z=0$. These are resolved with baryonic (dark matter) mass resolution of $8.5\times 10^4\rm {\rm M}_{\odot }$ ($4.5\times 10^5\rm {\rm M}_{\odot }$) and $\sim 150$ pc of average gas spatial resolution in the star-forming regions. The majority of TNG50 MW/M31 analogues at $z=0$ exhibit a bar, 60 per cent are star-forming, the sample includes three Local Group-like systems, and a number of galaxies host one or more satellites as massive as, for example, the Magellanic Clouds. Even within such a relatively narrow selection, TNG50 reveals a great diversity in galaxy and halo properties, as well as in past histories. Within the TNG50 sample, it is possible to identify several simulated galaxies whose integral and structural properties are consistent, one or more at a time, with those measured for the Galaxy and Andromeda. With this paper, we document and release a series of broadly applicable data products that build upon the IllustrisTNG public release and aim to facilitate easy access and analysis by public users. These include datacubes across snapshots ($0 \le z \le 7$) for each TNG50 MW/M31-like galaxy, and a series of value-added catalogues.

Power law cosmology in modified theory with thermodynamics analysis

We study a model in f(R,G) gravity described as a linear combination of R and an exponential function of G. We constrain the dependent parameters H0 and the deceleration parameter q using the latest 77 points of the OHD data, 1395 points of the Pantheon, Gamma Ray Burst, Gold data (PGG) and the joint data OHD+PGG and compare the results with the ΛCDM. Also, we speculate constraints using a simulated data set for the future JDEM (Joint Dark Energy Mission)/Omega, supernovae survey. We see that our results in power law cosmology are a better fit with the PGG data than the earlier analysis (Kumar, 2012; Rani, 2015). However, the constraints obtained on H average, <H0> and q average, <q> using the simulated data set for the future JDEM/Omega, supernovae survey are found to be inconsistent with the values obtained from the OHD and the PGG data. Additionally, we discuss statefinder diagnostics and see that the power law models approach the standard ΛCDM model (q→−1). This model satisfies the Generalized Second Law of Thermodynamics. Finally, we conclude that the power law cosmology in f(R,G) gravity explains most of the distinguished attributes of evolution in cosmology.

A Tale of Many H0

▪The Hubble parameter, H 0, is not an univocally defined quantity: It relates redshifts to distances in the near Universe, but it is also a key parameter of the ΛCDM standard cosmological model. As such, H 0 affects several physical processes at different cosmic epochs and multiple observables. We have counted more than a dozen H 0s that are expected to agree if (a) there are no significant systematics in the data and their interpretation and (b) the adopted cosmological model is correct.▪With few exceptions (proverbially confirming the rule), these determinations do not agree at high statistical significance; their values cluster around two camps: the low (68 km s1 Mpc1) and high (73 km s1 Mpc1) camps. It appears to be a matter of anchors. The shape of the Universe expansion history agrees with the model; it is the normalizations that disagree.▪Beyond systematics in the data/analysis, if the model is incorrect, there are only two viable ways to “fix” it: by changing the early time (z ≳ 1,100) physics and, thus, the early time normalization or by a global modification, possibly touching the model's fundamental assumptions (e.g., homogeneity, isotropy, gravity). None of these three options has the consensus of the community.▪The research community has been actively looking for deviations from ΛCDM for two decades; the one we might have found makes us wish we could put the genie back in the bottle.

Cosmic-dawn 21-cm signal from dynamical dark energy

The 21-cm signal is the most important measurement for us to understand physics during cosmic dawn. It is the key for us to understand the expansion history of the Universe and the nature of dark energy. In this paper, we focused on the characteristic 21-cm power spectrum of a special dynamic dark energy – the Interacting Chevallier-Polarski-Linder (ICPL) model – and compared it with those of the ΛCDM and CPL models. From the expected noise of HERA, we found more precise experiments in the future can detect the features of interacting dark energy in the 21-cm power spectra. By studying the brightness temperature, we found the ICPL model is closer to the observation of EDGES compared to the ΛCDM, thus alleviating the tension between theory and experiments.

From de Sitter to de Sitter: A Thermal Approach to Running Vacuum Cosmology and the Non-Canonical Scalar Field Description

The entire classical cosmological history between two extreme de Sitter vacuum solutions is discussed based on Einstein’s equations and non-equilibrium thermodynamics. The initial non-singular de Sitter state is characterised by a very high energy scale, which is equal or smaller than the reduced Planck mass. It is structurally unstable, and all of the continuous created matter, energy, and entropy of the material component comes from the irreversible flow powered by the primeval vacuum energy density. The analytical expression describing the running vacuum is obtained from the thermal approach. It opens a new perspective to solve the old puzzles and current observational challenges plaguing the cosmic concordance model driven by a rigid vacuum. Such a scenario is also modelled through a non-canonical scalar field. It is demonstrated that the resulting scalar field model is shown to be a step-by-step a faithful analytical representation of the thermal running vacuum cosmology.

Understanding the origin of early-type dwarfs: the spectrophotometric study of CGCG014−074

ABSTRACT Early-type dwarf galaxies constitute a prevalent population in the central regions of rich groups and clusters in the local Universe. These low-luminosity and low-mass stellar systems play a fundamental role in the assembly of the luminous galaxies observed today, according to the Lambda cold dark matter hierarchical theory. The origin of early-type dwarfs has been linked to the transformation of disc galaxies interacting with the intracluster medium, especially in dense environments. However, the existence of low-luminosity early-type galaxies in low-density environments presents a challenge to this scenario. This study presents a comprehensive photometric and spectroscopic analysis of the early-type dwarf galaxy CGCG014−074 using deep Gemini GMOS (Gemini Multi-Object Spectrograph) data, focusing on its peculiarities and evolutionary implications. CGCG014−074 exhibits distinct features, including a rotating inner disc, an extended stellar formation with a quiescent phase since about 2 Gyr ago, and the presence of boxy isophotes. From the kinematic analysis, we confirm CGCG014−074 as a nucleated early-type dwarf galaxy with embedded disc. The study of its stellar population parameters using different methods provides significant insights into the galaxy’s evolutionary history. These results show an old and metal-poor nucleus (${\sim}9.3$ Gyr and $\mathrm{[Z/H]}\sim -0.84$ dex), while the stellar disc is younger (${\sim}4.4$ Gyr) with a higher metallicity ($\mathrm{[Z/H]}\sim -0.40$ dex). These distinctive features collectively position CGCG014−074 as a likely building block galaxy that has evolved passively throughout its history.

[formula omitted]-Cosmological Boundary Flux Parameter

Efforts to explain the current accelerated expansion of the universe have prompted the investigation of different scenarios characterised by dark energy models. In this study, we explore an extended ωCBFP model, incorporating two commonly used parameterisations of ω(z) in terms of the redshift z: ω(z)=ω0 and ω(z)=ω0+ω1z/(1+z). In this context, the cosmological parameter Λ is directly linked to the dark matter component through a barotropic framework, where Λ acts as the source of ρcdm, characterised by a dimensionless constant λ, and directly dependent on Λω(z)CDM, which is fully defined by a specific ω(z) functional form. Through a statistical analysis, using late-time data of observational Hubble and type Ia Supernovae, we computed the joint best-fit value of the free parameters by means of the affine-invariant MCMC. On the one hand, the ω0CBFP instance shows an unexpected larger Ω0cdm contribution than the current Ω0Λ. Remarkably this outcome has not been previously reported (to our knowledge). On the other hand, in the ω0ω1CBFP example the dark energy component makes up nearly 60% of the total matter-energy at z=0, compared to just 36% for the cold dark matter contribution. This last result aligns more with the conventional ΛCDM model. In both instances there are unusual increases in Ωcdm(z) around z=1; however, these rises are offset by a decrease in Ωb(z).

Anisotropic Cosmological Model with SQM in f(R, Lm) Gravity

A locally rotationally symmetric Bianchi-I model filled with strange quark matter (SQM) is explored in f(R, Lm) gravity as a non-linear functional of the form f(R, Lm)=R/2 +Lαm, where α is the free model parameter. We considered the special law of variation of Hubble’s parameter proposed by Berman (1983) and also used the power law relation between the scale factors to obtain the exact solution of the field equation, which matches the model of the universe. We also analyze the physical and geometrical aspects of the universe’s kinematic and dynamic behavior. Additionally, we employ equation-of-state (EoS) parameters and statefinder parameters as analytical tools to gain insights into the evolution of the universe. We use the ΛCDM model as a benchmark to validate the results. By placing the deviations of the universe from ΛCDM model and yet making important contributions to the study of the anisotropic nature of f(R, Lm) gravity within the framework of cosmological dynamics, the paper increases our comprehension of our cosmic evolution.

Euclid preparation

Verifying the fully kinematic nature of the long-known cosmic microwave background (CMB) dipole is of fundamental importance in cosmology. In the standard cosmological model with the Friedman–Lemaitre–Robertson–Walker (FLRW) metric from the inflationary expansion, the CMB dipole should be entirely kinematic. Any non-kinematic CMB dipole component would thus reflect the preinflationary structure of space-time probing the extent of the FLRW applicability. Cosmic backgrounds from galaxies after the matter-radiation decoupling should have a kinematic dipole component identical in velocity to the CMB kinematic dipole. Comparing the two can lead to isolating the CMB non-kinematic dipole. It was recently proposed that such a measurement can be done using the near-infrared cosmic infrared background (CIB) measured with the currently operating Euclid telescope, and later with Roman. The proposed method reconstructs the resolved CIB, the integrated galaxy light (IGL), from Euclid’s Wide Survey and probes its dipole with a kinematic component amplified over that of the CMB by the Compton–Getting effect. The amplification coupled with the extensive galaxy samples forming the IGL would determine the CIB dipole with an overwhelming signal-to-noise ratio, isolating its direction to sub-degree accuracy. We developed details of the method for Euclid’s Wide Survey in four bands spanning from 0.6 to 2 μm. We isolated the systematic and other uncertainties and present methodologies to minimize them, after confining the sample to the magnitude range with a negligible IGL–CIB dipole from galaxy clustering. These include the required star–galaxy separation, accounting for the extinction correction dipole using the new method developed here achieving total separation, and accounting for the Earth’s orbital motion and other systematic effects. Finally, we applied the developed methodology to the simulated Euclid galaxy catalogs, successfully testing the upcoming applications. With the techniques presented, one would indeed measure the IGL–CIB dipole from Euclid’s Wide Survey with high precision, probing the non-kinematic CMB dipole.

The impact of constrained interacting dark energy on the bound-zone velocity profile

We numerically study the effects of constrained interacting dark energy (CIDER) on the bound-zone velocity profiles around massive dark matter halos. Analyzing the CIDER simulations performed by ref. [1] for three different cases of dark sector coupling (β = 0.03, 0.05 and 0.08) as well as for the standard ΛCDM cosmology (β = 0), we determine the mean peculiar velocity profiles in the bound zones around the friends-of-friends halos with masses larger than M cut = 3 × 1013 h-1 M ⊙ at three redshifts, z = 0, 0.5 and 1. It is found that the universal power-law formula proposed by ref. [2] originally for the ΛCDM case still describes well the bound-zone velocity profiles, V(r), even in the CIDER models. The slope of V(r), turns out to be significantly affected by the CIDER, progressively decreasing as β increases. Meanwhile, the amplitude of V(r) exhibits little dependence on β, which is ascribed to the identical Hubble parameters shared by the ΛCDM and CIDER models in the entire redshift range. Our results imply that the bound-zone velocity slope can break a degeneracy even between the ΛCDM and CIDER models with β ≤ 0.03, which the standard cosmological diagnostics fail to distinguish. We devise a simple analytic formula for the bound-zone slope as a function of β, and prove its validity at all of the three redshifts. It is concluded that the slope of the mean bound-zone peculiar velocity profile should be in principle a powerful probe of dark sector interaction.

A new diagnostic for the null test of dynamical dark energy in light of DESI 2024 and other BAO data

We introduce a new diagnostic for the null tests of dynamical dark energy alongside two other combined equivalent diagnostics. These diagnostics are useful, especially when we include anisotropic baryon acoustic oscillation (BAO) data in an analysis, to quantify the deviations from the standard ΛCDM model. We also consider another diagnostic for isotropic BAO observations. These null tests are independent of any late-time dark energy model or parametrization. With these diagnostics, we study the evidence for dynamical dark energy in light of Dark Energy Spectroscopic Instrument (DESI) 2024 data combined with cosmic microwave background (CMB) observations of the Planck 2018 mission and local H 0 measurements. We find no strong evidence for dynamical dark energy. The exclusion of the individual deviations at the effective redshift 0.51 of the DESI 2024 data makes the evidence even weaker. We get nearly similar results for other non-DESI BAO data. Both for DESI 2024 and other non-DESI BAO data, the evidence is almost independent of early-time physics. The evidence corresponding to the SHOES value of H 0 is higher than the corresponding tRGB value of H 0 for all combinations of data, but still not strong enough to reject the flat ΛCDM model.