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Laura O. Villegas

Publications and source records attributed to Laura O. Villegas.

3 recordsLinked to original sources

On the detectability of gravitational waves emitted from head-on collisions of $\ell$-boson stars

In this work, we investigate head-on collisions of $\ell$-boson stars, potential candidates for dark matter compact objects. We begin with a review of the general properties and features of these stars, leveraging results from prior studies to analyze the gravitational wave signals generated by such collisions. Considering a maximum distance of 100 Mpc for potential events, we identify the range of masses and scalar field frequencies for these stars that would render the gravitational waves detectable by current gravitational wave observatories. Additionally, we process the resulting signals to generate simulated observatory images, highlighting their similarities and differences compared to those produced by black hole collisions.

gr-qc↗

Parameter estimation from the core-bounce phase of rotating core collapse supernovae in real interferometer noise

In this work we propose an analytical model that reproduces the core-bounds phase of gravitational waves (GW) of Rapidly Rotating (RR) from Core Collapse Supernovae (CCSNe), as a function of three parameters, the arrival time $τ$, the ratio of the kinetic and potential energy $β$ and a phenomenological parameter $α$ related to rotation and equation of state (EOS). To validate the model we use 126 waveforms from the Richers catalog \cite{Richers_2017} selected with the criteria of exploring a range of rotation profiles, and involving EOS. To quantify the degree of accuracy of the proposed model, with a particular focus on the rotation parameter $β$, we show that the average Fitting Factor (FF) between the simulated waveforms with the templates is 94.4\%. In order to estimate the parameters we propose a frequentist matched filtering approach in real interferometric noise which does not require assigning any priors. We use the Matched Filter (MF) technique, where we inject a bank of templates considering simulated colored Gaussian noise and the real noise of O3L1. For example for A300w6.00\_BHBLP at 10Kpc we obtain a standar deviation of $σ= 3.34\times 10^{-3}$ for simulated colored Gaussian noise and $σ= 1.46\times 10^{-2}$ for real noise. On the other hand, from the asymptotic expansion of the variance we obtain the theoretical minimum error for $\hatβ$ at 10 kpc and optimal orientation. The estimation error in this case is from $10^{-2}$ to $10^{-3}$ as $β$ increases. We show that the results of the estimation error of $β$ for the 3-parameter space (3D) is consistent with the single-parameter space (1D), which allows us to conclude that $β$ is decoupled from the others two parameters.

gr-qc↗

Determination of the angular momentum of the Kerr black hole from equatorial geodesic motion

We present a method to determine the angular momentum of a black hole, based on observations of the trajectories of the bodies in the Kerr space-time. We use the Hamilton equations to describe the dynamics of a particle and present results for equatorial trajectories, obtaining an algebraic equation for the magnitude of the black hole's angular momentum. We tailor a numerical code to solve the dynamical equations and use it to generate synthetic data. We apply the method in some representative examples, obtaining the parameters of the trajectories as well as the black hole's angular momentum in good agreement with the input data.

gr-qc↗