Dark Halo Research Articles

Quantum model of galactic halos with an Navarro-Frenk-White dark matter profile

A quantum model of a cold dark matter galactic halo is developed. The model requires specifying the mass and radius of the halo as well as its density profile. The structure of the halo resulting from the theory is predicted and its physical properties are determined. Verification of these theoretical predictions by observations is proposed and discussed. The model is constructed by analytically solving the governing equation and using its time-independent solutions to determine the internal structure of a galactic halo with an Navarro-Frenk-White cold dark matter density profile. The governing equation that is the basis of the developed theory is derived from the irreducible representations of the extended Galilean group. The method of finding the solutions is analytical, even though an Navarro-Frenk-White density profile is used in the calculations. The theory predicts a halo with a core composed of free dark matter particles that move randomly with frequent collisions. It also predicts an envelope in which the particles are confined to their orbits, which are quantized. Except in the close vicinity of the core, the population of the orbits remains fixed, and physical reasons for the nonexistence of quantum jumps between these orbits are presented. A quantum model of a galactic cold dark matter halo with a given Navarro-Frenk-White density profile is constructed. It predicts a quantum structure of the halo that is significantly different than any previously known dark matter model. The quantum model naturally accounts for dark matter being collisionless, and it predicts that dark matter can only emit radiation of one fixed frequency. The values of this frequency are computed for dark matter particles of different masses. A potential observational verification of the theory is also discussed.

Characterising ultra-high-redshift dark matter halo demographics and assembly histories with the gureft simulations

Abstract Dark matter halo demographics and assembly histories are a manifestation of cosmological structure formation and have profound implications for the formation and evolution of galaxies. In particular, merger trees provide fundamental input for several modelling techniques, such as semi-analytic models (SAMs), sub-halo abundance matching (SHAM), and decorated halo occupation distribution models (HODs). Motivated by the new ultra-high-redshift (z ≳ 10) frontier enabled by JWST, we present a new suite of Gadget at Ultrahigh Redshift with Extra-Fine Timesteps (gureft) dark matter-only cosmological simulations that are carefully designed to capture halo merger histories and structural properties in the ultra-z universe. The simulation suite consists of four 10243-particle simulations with box sizes of 5, 15, 35, and 90 Mpc h−1, each with 170 snapshots stored between 40 ≥ z ≥ 6. With the unprecedented number of available snapshots and strategically chosen dynamic range covered by these boxes, gureft uncovers the emerging dark matter halo populations and their assembly histories in the earliest epochs of cosmic history. In this work, we present the halo mass functions between z ∼ 20 to 6 down to log (Mvir/M⊙) ∼ 5, and show that at high redshift, these robust halo mass functions can differ substantially from commonly used analytic approximations or older fitting functions in the literature. We also present key physical properties of the ultra-high z halo population, such as concentration and spin, as well as their mass growth and merger rates, and again provide updated fitting functions.

From inflation to dark matter halo profiles: the impact of primordial non-Gaussianities on the central density cusp

It has recently been shown that local primordial non-Gaussianities (PNG) with significant amplitude (|f NL| ∼ 1000), at small (Mpc) scales, can help in forming simulated galaxies with more disky baryonic kinematics than in the Gaussian case, while generating matter power spectra that can differ by up to 20% from the Gaussian case at non-linear scales. Here, we explore in detail the consequences of such small-scale PNG on the dark matter halo profiles. We show in particular that, for negative f NL, dark matter halos formed in collisionless simulations are not always well described by the traditional Navarro-Frenk-White (NFW) profiles, as supported by their sparsity distribution. We conclude that NFW profiles are not as clear attractors for the density profiles of dark matter halos in the presence of PNG than in the case of a Gaussian contrast density field. We show how alternatives to the NFW profile can describe halos both in the Gaussian and non-Gaussian cases. From the combination of our sparsity analysis and the quality of the adjustments of the density profiles with a minimal extension to NFW, we conclude that z = 1 halos carry the most interesting information about PNG.

The Next Generation Virgo Cluster Survey (NGVS). XXVII. The Size and Structure of Globular Cluster Systems and Their Connection to Dark Matter Halos

We study the size and structure of globular cluster (GC) systems of 118 early-type galaxies from the NGVS, MATLAS, and ACSVCS surveys. Fitting Sérsic profiles, we investigate the relationship between effective radii of GC systems (R e,gc) and galaxy properties. GC systems are 2–4 times more extended than host galaxies across the entire stellar mass range of our sample (108.3 M ⊙ < M * < 1011.6 M ⊙). The relationship between R e,gc and galaxy stellar mass exhibits a characteristic “knee” at a stellar mass of M p ≃ 1010.8, similar to the galaxy R e –stellar mass relationship. We present a new characterization of the traditional blue and red GC color subpopulations, describing them with respect to host galaxy (g′−i′) color (Δgi): GCs with similar colors to their hosts have a “red” Δgi, and those significantly bluer GCs have a “blue” Δgi. The GC populations with red Δgi, even in dwarf galaxies, are twice as extended as the stars, suggesting that formation or survival mechanisms favor the outer regions. We find a tight correlation between R e,gc and the total number of GCs, with intrinsic scatter ≲0.1 dex spanning two and three orders of magnitude in size and number, respectively. This holds for both red and blue subpopulations, albeit with different slopes. Assuming that N GC,Total correlates with M 200, we find that the red GC systems have effective radii of roughly 1%–5% R 200, while the blue GC systems in massive galaxies can have sizes as large as ∼10% R 200. Environmental dependence on R e,gc is also found, with lower-density environments exhibiting more extended GC systems at fixed mass.

Distortions of the Hubble diagram: Line-of-sight signatures of local galaxy clusters

The Universe expansion rate is modulated around local inhomogeneities due to their gravitational potential. Velocity waves are then observed around galaxy clusters in the Hubble diagram. This paper studies them in a sim 738 Mpc-wide, 2048$^3$-particle cosmological simulation of our cosmic environment (a.k.a. CLONE: Constrained LOcal Nesting Environment Simulation). For the first time, the simulation shows that velocity waves that arise in the lines of sight of the most massive dark matter halos agree with those observed in local galaxy velocity catalogs in the lines of sight of Coma and several other local (Abell) clusters. For the best-constrained clusters such as Virgo and Centaurus -- that is, those closest to us -- secondary waves caused by galaxy groups, further into the non-linear regime, also stand out. This match was not utterly expected given that before being evolved into a fully non-linear z=0 state, assuming Lambda CDM, CLONE initial conditions are constrained solely with linear theory, the power spectrum, and highly uncertain and sparse local peculiar velocities. Additionally, Gaussian fits to velocity wave envelopes show that wave properties are tightly tangled with cluster masses. This link is complex, though, and involves the environment and formation history of the clusters. A proposed metric, measuring the distance between the observed and several re-centred simulated lines of sight, waves included, is shown to be capable of providing a tight mass range estimate for massive local clusters. Using machine learning techniques to grasp more thoroughly the complex wave-mass relation, velocity waves could in the near future be used to provide additional and independent mass estimates from galaxy dynamics within large cluster radii.

Three-dimensional stellar orbits due to off-centered dark matter halo at the center of the disc galaxies

Three-dimensional stellar orbits due to off-centered dark matter halo at the center of the disc galaxies

The missing quasar image in the gravitationally lensed quasar HE0230−2130: Implications for the cored lens mass distribution and dark satellites

Strongly lensed systems with peculiar configurations allow us to probe the local properties of the deflecting lens mass while simultaneously testing general profile assumptions. The quasar HE0230−2130 is lensed by two galaxies at similar redshifts (Δz ∼ 0.003) into four observed images. Using modeled quasar positions from fitting the brightness of the quasar images in ground-based imaging data from the Magellan telescope, we find that lens-mass models where each of these two galaxies is parametrized with a singular power-law (PL) profile predict five quasar images. One of the predicted images is unobserved despite it being distinctively offset from the lensing galaxies and likely bright enough to be observable. This missing image gives rise to new opportunities to study the mass distribution of these galaxies. To interpret the quad configuration of the system, we tested 12 different profile assumptions with the aim of obtaining lens-mass models that correctly predict only four observed images. We tested the effects of adopting: cored profiles for the lensing galaxies; external shear; and additional profiles to represent a dark matter clump. We find that half of our model classes can produce the correct image multiplicity. By comparing the Bayesian evidence of different model parametrizations, we favor two model classes: (i) one that incorporates two singular PL profiles for the lensing galaxies and a cored isothermal sphere in the region of the previously predicted fifth image (rNIS profile), and (ii) one with a bigger lensing galaxy parametrized by a singular PL profile and the smaller galaxy by a cored PL profile with external shear. We estimated the mass of the rNIS clump for each candidate model of our final Markov chain Monte Carlo sample, and find that only 2% are in the range of 106 M⊙ ≤ MrNIS ≤ 109 M⊙, which is the predicted mass range of dark matter subhalos in cold dark matter simulations, or the mass of dark-matter-dominated and low-surface-brightness galaxies. We therefore favor the models with a cored mass distribution for the lens galaxy close to the predicted fifth image. Our study further demonstrates that lensed quasar images are sensitive to the dark matter structure in the gravitational lens. We are able to describe this exotic lensing configuration with relatively simple models, which demonstrates the power of strong lensing for studying galaxies and lens substructure.

A dusty proto-cluster surrounding the binary galaxy HerBS-70 at z = 2.3

Abstract We report on deep SCUBA-2 observations at 850 μm and NOEMA spectroscopic measurements at 2 mm of the environment surrounding the luminous, massive (M* ≈ 2 × 1011 M⊙) Herschel-selected source HerBS-70. This source was revealed by previous NOEMA observations to be a binary system of dusty star-forming galaxies at z = 2.3, with the East component (HerBS-70E) hosting an Active Galactic Nucleus (AGN). The SCUBA-2 observations detected, in addition to the binary system, twenty-one sources at &amp;gt;3.5σ over an area of ∼25 square comoving Mpc with a sensitivity of 1σ850 = 0.75 mJy. The surface density of continuum sources around HerBS-70 is three times higher than for field galaxies. The NOEMA spectroscopic measurements confirm the protocluster membership of three of the nine brightest sources through their CO(4–3) line emission, yielding a volume density 36 times higher than for field galaxies. All five confirmed sub-mm galaxies in the HerBS-70 system have relatively short gas depletion times (80 − 500 Myr), indicating the onset of quenching for this protocluster core due to the depletion of gas. The dark matter halo mass of the HerBS-70 system is estimated around 5 × 1013 M⊙, with a projected current-day mass of 1015 M⊙, similar to the local Virgo and Coma clusters. These observations support the claim that DSFGs, in particular the ones with observed multiplicity, can trace cosmic overdensities.

The host dark matter haloes of the first quasars

Abstract If z &amp;gt; 6 quasars reside in rare, massive haloes, ΛCDM cosmology predicts they should be surrounded by an anomalously high number of bright companion galaxies. Here I show that these companion galaxies should also move unusually fast. Using a new suite of cosmological, ‘zoom-in’ hydrodynamic simulations, I present predictions for the velocity distribution of quasar companion galaxies and its variation with quasar host halo mass at z = 6. Satellites accelerate as they approach the quasar host galaxy, producing a line-of-sight velocity profile that broadens with decreasing distance to the quasar host galaxy. This increase in velocity dispersion is particularly pronounced if the host halo mass is $\gtrsim 5 \times 10^{12} \, \rm M_\odot$. Typical line-of-sight speeds rise to $\approx 500 \, \rm km \, s^{-1}$ at projected radii $\sim 10 \, \rm kpc$. For about $10\%$ of satellites, they should exceed $800 \, \rm km \, s^{-1}$, with $\approx 5\%$ of companions reaching line-of-sight speeds $\sim 1000 \, \rm km \, s^{-1}$. For lower host halo masses $\approx 5 \times 10^{11} -10^{12} \, \rm M_\odot$, the velocity profile of companion galaxies is significantly flatter. In this case, typical line-of-sight velocities are $\approx 250 \, \rm km \, s^{-1}$ and do not exceed $\approx 500 \, \rm km \, s^{-1}$. A comparison with existing ALMA, JWST and MUSE line-of-sight velocity measurements reveals that observed z &amp;gt; 6 quasar companions closely follow the velocity distribution expected for a host halo with mass $\gtrsim 5 \times 10^{12} \, \rm M_\odot$, ruling out a light host halo. Finally, through an estimate of UV and [$\rm O \, {\small III}$] luminosity functions, I show that the velocity distribution more reliably discriminates between halo mass than companion number counts, which are strongly affected by cosmic variance.

Inferring Properties of Dark Galactic Halos Using Strongly Lensed Gravitational Waves

Abstract Gravitational waves (GWs) can be deflected, similarly to electromagnetic (EM) waves, by massive objects through the phenomenon of gravitational lensing. The importance of GW lensing for GW astronomy is becoming increasingly apparent in the GW detection era, in which nearly 100 events have already been detected. As current ground-based interferometers reach their design sensitivities, it is anticipated that these detectors may observe a few GW signals that are strongly lensed by the dark halos of intervening galaxies or galaxy clusters. Analyzing the strong lensing effects on GW signals is, thus, becoming important to understand the lens’ properties and correctly infer the intrinsic GW source parameters. However, one cannot accurately infer lens parameters for complex lens models with only GW observations because there are strong degeneracies between the parameters of lensed waveforms. In this paper, we discuss how to conduct parameter estimation of strongly lensed GW signals and infer the lens parameters using additional EM information, including the lens galaxy’s axis ratio and the GW source-hosting galaxy’s lensed images. We find that for simple spherically symmetric lens models, the lens parameters can be well recovered using only GW information. On the other hand, recovering the lens parameters requires systems in which four or more GW images are detected with additional EM observations for nonaxially symmetric lens models. Combinations of GW and EM observations can further improve the inference of the lens parameters.

GN-z11: The environment of an active galactic nucleus at z=10.603. New insights into the most distant Ly alpha detection

Recent observations with the James Webb Space Telescope (JWST) have further refined the spectroscopic redshift of GN-z11, one of the most distant galaxies identified with the Hubble Space Telescope, at $z=10.603$. The presence of extremely dense gas ($&gt;10^ $ cm$^ $), the detection of high-ionisation lines and of CII*1335 emission, and the presence of an ionisation cone indicate that GN-z11 also hosts an active galactic nucleus. Further photometric and spectroscopic follow-up demonstrates that it lies in a large-scale, overdense structure with possible signatures of Population III stars in its halo. Surprisingly, Lyalpha has also been detected despite the expected largely neutral intergalactic medium at such a redshift. We exploit recent JWST/NIRSpec integral field unit observations to demonstrate that the Lyalpha emission in GN-z11 is part of an extended halo with a minimum size of 0.8--3.2 kpc, depending on the definition used to derive the halo size. The surface brightness of the Lyalpha halo around GN-z11 appears consistent with Lyalpha halos observed around $z quasars. At the wavelength of Lyalpha at $z we identify three other emission line candidates within the integral field unit field of view with no UV rest-frame counterpart visible in deep images from the JWST/NIRCam. If confirmed, this could be the first evidence that the local region of GN-z11 represents a candidate protocluster core, forming just 400 Myr after the Big Bang. We give a first estimate of the dark matter halo mass of this structure odot $), which is consistent with a Coma-like cluster progenitor.

Halo Asymmetry in the Modeling of Galaxy Clustering

Conventional studies of galaxy clustering within the framework of halo models typically assume that the density profile of all dark matter halos can be approximated by the Navarro–Frenk–White (NFW) spherically symmetric profile. However, both modern N-body simulations and observational data suggest that most halos are either oblate or prolate, and almost never spherical. In this paper we present a modified model of the galaxy correlation function. In addition to the five “classical” halo occupation distribution (HOD) parameters proposed by Zheng et al., it includes an additional free parameter ϕ in the modified NFW density profile describing the asymmetry of the host dark matter halo. Using a subhalo abundance matching model, we populate galaxies within BolshoiP N-body simulations. We compute the projected two-point correlation function w p (r p ) for six stellar-mass volume-limited galaxy samples. We fit our model to the results and then compare the best-fit asymmetry parameter ϕ (and other halo parameters) to the asymmetry of dark matter halos measured directly from the simulations and find that they agree within 1σ. We then fit our model to the w p (r p ) results from Zehavi et al. and compare halo parameters. We show that our model accurately retrieves the halo asymmetry and other halo parameters. Additionally, we find 2%–6% differences between the halo masses ( logMmin and logM 1) estimated by our model and those estimated by “classical” HOD models. The model proposed in this paper can serve as an alternative to multiparameter HOD models, since it can be used for relatively small samples of galaxies.

Analysis of Choriocapillaris Reperfusion Topography following Faricimab Treatment for Neovascular Age-Related Macular Degeneration in Non-Treatment-Naïve Patients

To assess changes in choriocapillaris (CC) vascular density surrounding macular neovascularization (MNV) in age-related macular degeneration (AMD) when transitioning from various anti-VEGF treatments to faricimab, using optical coherence tomography angiography (OCTA). 25 eyes of 22 individuals who underwent intravitreal faricimab injections for neovascular AMD with type 1 MNV were included. OCTA images were obtained prior to (T0), after one (T1), and after three faricimab injections (T2); Noteworthy changes occurred in the first ring at T2 in comparison to T0. The percentage of CC flow deficit (FD%), FD average area (FDa), and FD number (FDn) in 5 rings (R1-R5) surrounding the dark halo around the MNV were calculated. A reduction in FD% at T2 compared to T0 (50.5 ± 10.2% at T0, 46.4 ± 10.6% at T2; p = 0.020) was seen, indicating CC reperfusion. Additionally, we observed a reduction in the average FDa (140.2 ± 172.1% at T0, 93.7 ± 101.8% at T2; p = 0.029). Our study highlights an FD% after three consecutive faricimab injections. The most pronounced effect was observed in the first ring, directly adjacent to the dark halo, suggesting a partial CC reperfusion surrounding the MNV, potentially indicating disease regression.

Dynamical stability of new wormhole solutions via cold dark matter and solitonic quantum wave halos in [formula omitted] gravity

This current analysis offers novel wormhole solutions in the background of newly developed extended f(R,Lm) gravity. We use an anisotropic matter source and a particular type of energy density demonstrating cold dark matter halo and quantum wave dark matter halo to calculate two different wormhole solutions. The properties of the exotic matter within the wormhole geometry and the matter contents via energy conditions are studied in detail, both analytically and graphically, by showing valid and invalid regions. The calculated shape functions of wormhole geometry satisfy the required conditions in both cases. Further, we investigate the stability of the shell around wormhole structures by considering black hole solutions in the framework of cold dark matter halo and quantum wave dark matter by assuming matter contents located at the shell follow the phantom-like equations of state. Then, for quintessence and phantom energy type equations of state, the choice of cold dark matter halo has maximum stability at lower equilibrium shell radii and declines as the radius rises. More petite wormhole throats have an unstable configuration for the dark energy matter content, while higher wormhole throat radius has the lowest stability. For the choice of quantum wave dark matter, the shell around the wormhole structure is unstable for both quintessence and phantom energy, while dark energy shows a stable configuration for smaller values of wormhole throat.

Generalized molecule-like structure in atomic nuclei

Starting from a |ϕ|4 field theory with universal pn interacting angular and distance coordinates (θ,r) to depict nuclear long-range correlations, we have derived a cubic Schrödinger equation for NpNnpn interacting virtual bosons, which are believed to dominate the generic evolution of nuclear structure from spherical multi-nucleon shell-model states to deformed collective rotational states. It is shown that two-soliton solution in θ space manifests two opposite pn-type Ising-like chains existing in ground states and their gradual alignment responsible for nuclear rotational excitations. Of particular prominence is two-soliton solution with respect to r: the mutual relative motion of valence protons and neutrons around valence-nucleon mass centers considered as the dynamic equilibrium positions of a non-linear Schrödinger breather. And the resulting non-vanishing root mean square 〈r2〉 divides half the valence nucleons belonging to a chain into four local mass centers and proposes two chain-corresponding molecule-like tetrads outside inert cores pairwise hidden in ground states. Such solitons turn out to be an analogue of opposite axion fluids around a local mass center in the galactic dark-matter halo outside the soliton core (Garnier et al. (2021) [67]) and the present study facilitates making the latter more clear. The generalized molecule-like structure arouses a requisite to the addition of cluster-interior and cluster-to-core electric dipole moments in particular to pear-shaped nuclei, whose variants Schiff moments play an important role in measuring diamagnetic atomic electric dipole moments and therefore understanding CP-violating new physics beyond the standard model. We put additional parts in evidence by befitting the NpNn scheme verified already by electric quadrupole moments in same nuclei.

Dynamical modelling and the origin of gas turbulence in z~4.5 galaxies

In recent years, a growing number of regularly rotating galaxy discs have been found at z geq 4. Such systems provide us with the unique opportunity to study the properties of dark matter (DM) halos at these early epochs, the turbulence within the interstellar medium and the evolution of scaling relations. Here, we investigate the dynamics of four gas discs in galaxies at z sim 4.5 observed with ALMA in the CII 158 mu m fine-structure line. We aim to derive the structural properties of the gas, stars and DM halos of the galaxies and to study the mechanisms driving the turbulence in high- z discs. We decomposed the rotation curves into baryonic and DM components within the extent of the CII discs, that is, 3 to 5 kpc. Furthermore, we used the gas velocity dispersion profiles as a diagnostic tool in investigating the mechanisms driving the turbulence in the discs. We obtain total stellar, gas and DM masses in the ranges of $ (M/M_ odot = 10.3 - 11.0$, $9.8 - 11.3$, and $11.2 - 13.3$, respectively. We find dynamical evidence in all four galaxies for the presence of compact stellar components conceivably, stellar bulges. The turbulence present in the galaxies appears to be primarily driven by stellar feedback, negating the necessity for large-scale gravitational instabilities. Finally, we investigate the position of our galaxies in the context of local scaling relations, in particular the stellar-to-halo mass and Tully-Fisher analogue relations.

Improving and extending non-Poissonian distributions for satellite galaxies sampling in HOD: applications to eBOSS ELGs

ABSTRACT Halo occupation distribution (HOD) models help us to connect observations and theory, by assigning galaxies to dark matter haloes. In this work, we study one of the components of HOD models: the probability distribution function (PDF), which is used to assign a discrete number of galaxies to a halo, given a mean number of galaxies. For satellite galaxies, the most commonly used PDF is a Poisson Distribution. PDFs with super-Poisson variances have also been studied, allowing for continuous values of variances. This has not been the case for sub-Poisson variances, for which only the nearest integer distribution, with a single variance, has been used in the past. In this work, we propose a distribution based on the binomial one, which provides continuous sub-Poisson variances. We have generated mock galaxy catalogues from two dark-matter only simulations, unit and outerrim, with HOD models assuming different PDFs. We show that the variance of the PDF for satellite galaxies affects the one-halo term of the projected correlation function, and the count-in-cells (CIC) one point statistics. We fit the clustering of eBOSS emission line galaxies, finding results consistent with the literature, when we only vary the parameter controlling the PDF variance and the fraction of satellites. Using a mock catalogue as a reference, we have also included both the clustering and CIC to constrain the parameters of the HOD model. CIC can provide strong constraints to the PDF variance of satellite galaxies.

New insights on the dynamics of satellite galaxies: Effects of the figure rotation of a host galaxy

Abstract We investigate a mechanism to form and keep a planar spatial distribution of satellite galaxies in the Milky Way (MW), which is called the satellite plane. It has been pointed out that the ΛCDM cosmological model hardly explains the existence of such a satellite plane, so it is regarded as one of the serious problems in the current cosmology. We here focus on a rotation of the gravitational potential of a host galaxy, i.e., a so-called figure rotation, following the previous suggestion that this effect can induce the tilt of a so-called tube orbit. Our calculation shows that a figure rotation of a triaxial potential forms a stable orbital plane perpendicular to the rotational axis of the potential. Thus, it is suggested that the MW’s dark halo is rotating with its axis being around the normal line of the satellite plane. Additionally, we find that a small velocity dispersion of satellites is required to keep the flatness of the planar structure, namely the standard derivation of their velocities perpendicular to the satellite plane needs to be smaller than their mean rotational velocity on the plane. Although not all the MW’s satellites satisfy this condition, a fraction of them, called member satellites, which are prominently on the plane, do satisfy it. We suggest that this picture explaining the observed satellite plane can be achieved by the filamentary accretion of dark matter associated with the formation of the MW and a group infall of member satellites along this cosmic filament.

Elucidating the impact of massive neutrinos on halo assembly bias

ABSTRACT Massive neutrinos have non-negligible impact on the formation of large-scale structures. We investigate the impact of massive neutrinos on the halo assembly bias effect, measured by the relative halo bias $\hat{b}$ as a function of the curvature of the initial density peak $\hat{s}$, neutrino excess ϵν, or halo concentration $\hat{c}$, using a large suite of ΣMν = 0.0 and 0.4 eV simulations with the same initial conditions. By tracing dark matter haloes back to their initial density peaks, we construct a catalogue of halo ‘twins’ that collapsed from the same peaks but evolved separately with and without massive neutrinos, thereby isolating any effect of neutrinos on halo formation. We detect a 2 per cent weakening of the halo assembly bias as measured by $\hat{b}(\epsilon _\nu)$ in the presence of massive neutrinos. As there exists a significant correlation between $\hat{s}$ and ϵν (rcc = 0.319), the impact of neutrinos persists at a reduced level (0.1 per cent) in the halo assembly bias measured by $\hat{b}(\hat{s})$. However, we do not detect any neutrino-induced impact on $\hat{b}(\hat{c})$, consistent with earlier studies and the lack of correlation between $\hat{c}$ and ϵν (rcc = 0.087). We also discover an analogous assembly bias effect for the ‘neutrino haloes’, whose concentrations are anticorrelated with the large-scale clustering of neutrinos.

Wormhole solutions under the effect of dark matter in f(R, L m ) gravity

In the background of f(R, L m ) gravity, this work investigates three distinct dark matter halo profiles to test the possibility of generalised wormhole geometry within the galactic halo regions. The current study aims to accomplish these goals by examining various dark matter profiles including universal rotation curves (URC), Navarro–Frenk–White (NFW) model-I, and NFW model-II inside two distinct f(R, L m ) gravity models. According to the f(R,Lm)=R2+Lmα model, the dark matter (DM) halo density profiles produce suitable shape functions that meet all the necessary requirements for exhibiting the wormhole geometries with appropriate choice of free parameters. In addition, to examine DM profiles under the f(R,Lm)=R2+(1+λR)Lm model, we consider a specific shape function. Further, we observed that the derived solution from both two models violates the null energy constraints, confirming that the DM supports wormholes to maintain in the galactic halo.