arXiv subjects

Jessica N. López-Sánchez

Publications and source records attributed to Jessica N. López-Sánchez.

5 recordsLinked to original sources

arXiv2026

Core-halo scaling relations in self-interacting scalar field dark matter

We study the impact of self-interactions on the structure and evolution of scalar field dark matter (SFDM) halos. Using three-dimensional Gross-Pitaevskii-Poisson simulations of multiple soliton mergers, we explore both repulsive and attractive regimes across a wide range of scattering lengths. Our results show that repulsive self-interactions lead to more massive and extended cores with lower central densities compared to the free (non-interacting) fuzzy dark matter case, while attractive interactions enhance central densities and can drive cores toward collapse, once a critical mass is exceeded. We confirm that the mass-radius relation of solitonic cores is well described by analytical predictions, even in the presence of self-interactions, and we extend the core-halo mass relation to scenarios beyond fuzzy dark matter. We find that the scaling relations between core mass, size, and total energy are not universal but depend sensitively on the strength and sign of the self-interaction, as well as on the evolutionary stage of the halo. These results demonstrate that self-interactions provide a natural mechanism to regulate core properties, with important implications for the formation of supermassive black holes and for potential astrophysical signatures in galactic cores.

astro-ph.CO↗

arXiv2026

Forecast on the generalised dark matter properties from a Euclid-like survey

The Stage~IV \textit{Euclid} mission will deliver spectroscopic galaxy redshifts together with photometric positions and shapes, enabling cosmological analyses through spectroscopic galaxy clustering (GCsp), photometric galaxy clustering (GCph), weak-lensing cosmic shear (WL), and their cross-correlation (XC). In this work we forecast the constraining power of a Euclid-like survey on the Generalised Dark Matter (GDM) parameters $w_{\rm gdm}$ and $c^{2}_{s,{\rm gdm}}$. Our analysis extends previous forecasting pipeline used for standard cold dark matter. For GCsp, we adopt a semi-analytic nonlinear RSD model, with free terms for each bin. For the photometric probes, we compute the nonlinear GDM matter power spectrum using dedicated simulations, and we modify the lensing and clustering window and the intrinsic-alignment prescription. We consider several survey configurations and explore three fiducial values of $σ_8$ motivated by current CMB and low-redshift measurements. In an optimistic setting, for fiducial values $σ_8 \simeq 0.81$ and $σ_8 \simeq 0.77$, we find relative errors of $4.01\%$ (GCsp), $5.01\%$ (GCph+WL+XC), and $1.96\%$ (all probes) on $c^{2}_{s,{\rm gdm}}$, and $3.26\%$ (GCph+WL+XC) and $1.85\%$ (all probes) on $w_{\rm gdm}$. For a lower fiducial value $σ_8 \simeq 0.67$, that could strongly disfavor $Λ$GDM, we find constraints of $5\%$ (GCsp), $5\%$ (GCph+WL+XC), and $2.45\%$ (all probes) on $c^{2}_{s,{\rm gdm}}$, and $3.43\%$ (GCph+WL+XC) and $2.04\%$ (all probes) on $w_{\rm gdm}$. We also found that, combining all probes, whether in the pessimistic or optimistic settings, a Euclid-like survey will be able to disentangle between the three scenarios. These results show that the survey will be able to constrain the GDM parameters and distinguish between normalisations of the matter fluctuations.(Abridged)

astro-ph.CO↗

arXiv2025

$S_8-H_0$ tension in a SI-ULDM scenario

We study the cosmological impact of a transient self-interaction phase in Ultra-Light Dark Matter (ULDM), focusing on its simultaneous effects on the sound horizon and the late-time growth of structure. In the presence of a quartic self-interaction, the scalar field undergoes a short-lived radiation-like phase before evolving into matter-like behaviour, inducing a localized modification of the expansion history at early times. We develop a perturbative and model-independent framework in which the self-interaction energy density is parametrized as a localized contribution to the total energy budget. Within this approach, the responses of the sound horizon and the linear growth factor can be expressed as weighted integrals over cosmic time, with distinct kernels encoding the temporal sensitivity of each observable. This structure leads to a simple analytic relation linking the corresponding early- and late-time responses, and naturally predicts correlated shifts in $H_0$ and $S_8$ whose sign and magnitude depend on the timing of the self-interaction episode. Our results show that a single transient modification of the expansion history can interpolate between early-time effects on the sound horizon and late-time suppression of structure growth within a unified physical framework, providing an analytical understanding of their joint response.

astro-ph.CO↗

arXiv2025

Scaling relations, dynamical heating and tidal disruption in spin $s$ ultralight dark matter models

We explore the impact of spin 0, spin 1 and spin 2 ultralight dark Matter (ULDM) on small scales by numerically solving the Schrödinger-Poisson system using the time-split method. We perform simulations of ULDM for each spin, starting with different numbers of identical initial solitons and analyse the properties of the resulting haloes after they merge. Our findings reveal that higher spin lead to broader, less dense haloes with more prominent Navarro-Frenk-White (NFW) tails, a characteristic that persists regardless of the number of solitons involved. Additionally, we study the process of dynamical heating for these haloes, and find that the heating time-scale for higher spin increases order an of magnitude compared to the spin 0 case. Then, we identify scaling relations that describe the density profile, core-NFW of spin~$s$ ULDM haloes as a function of the number of initial solitons $N_{\text{sol}}$. These relations allow us to construct equivalent haloes based on average density or total mass, for arbitrarily large $N_{\text{sol}}$, without having to simulate those systems. We simulate the orbit of an ULDM satellite in a constructed halo treated as an external potential, and find that for host haloes having the same average density, the disruption time of the satellite is as predicted for a uniform sphere regardless of the spin. However, satellites orbiting haloes having the same mass for each spin, result in faster disruption in the case of spin 0, whereas for haloes having the same core size result in faster disruption in the case of spin 2.

astro-ph.CO↗

arXiv2022

Compact Groups in GDM Cosmological Simulations

In this work, we study some properties of the Hickson Compact Groups (HCGs) using N-body simulations for the Generalized Dark Matter (GDM) model, described by three free functions, the sound speed, the viscosity and the equation of state. We consider three GDM models associated with different values of the free functions to neglect collisional effects. We constructed the initial seeds of our simulations according to the matter power spectrum of GDM linear perturbations, which hold a cut-off at small scales, and explored their effects on the non-linear structure formation at small and intermediate scales. We generated mock catalogues of galaxies for different models and classify HCGs by implementing an algorithm that adapts the original selection method for mock catalogues. Once the HCGs samples are classified, we analyzed their properties and compared them between models. We found that a larger amount of HCGs are counted in GDM simulations in comparison to CDM counts. This difference suggests that HCGs can proliferate within GDM despite the suppressed substructure, which indicates a possible modification in the HCG formation process within models where DM is not perfectly like CDM. Additionally, we identified different mechanisms of clustering, for models with a large amount of galaxy-halos self-agglomerate because of their abundance while models with fewer galaxy-halos need massive halos acting as a dominant potential well. Finally, by comparing distributions of different observables of simulated HCGs against observations, we found a good agreement in the intrinsic properties. However, a discrepancy in the velocity dispersion remains unsolved.

astro-ph.CO↗