arXiv subjects

Irvin Martinez

Publications and source records attributed to Irvin Martinez.

6 recordsLinked to original sources

arXiv2023

Modeling Compact Objects with EFT II: The Post-Newtonian Expansion

Part 2 of 3 from master's thesis: Modeling Compact Objects with Effective Field Theory. Using the Effective Field Theory framework for extended objects, we build the effective theory of a binary system made up of the most general compact objects in a theory of gravity as General Relativity with electrodynamics, objects which are described by their mass, spin, charge and their finite-size structure. We obtain the leading order post-Newtonian expansion to each of the relevant terms in the effective action that have been derived using the coset construction, where the covariant building blocks to build up the tower of invariant operators are derived from symmetry principles. Having matched the coefficients of the theory from the literature, we show the predictivity of our theory by obtaining well known post-Newtonian results on spinning extended objects, as well as on charged objects. Then, we bring new results on the polarizability and dissipation of charged spinning compact objects.

hep-th↗

arXiv2023

Modeling Compact Objects with Effective Field Theory I: The Effective Action

This is part 1 of 3 from the master's thesis: Modeling Compact Objects with Effective Field Theory, supervised by Amanda Weltman. Using the Effective Field Theory framework for extended objects and the coset construction, we build the leading order effective action for the most general compact object allowed in an effective theory of gravity as general relativity. By recognizing the symmetry breaking pattern of a charged spinning compact object, we derive all the covariant building blocks and constraints to build up the relevant invariant operators in the action to all orders. We derive the effective action for a spinning extended object and make the connection to currently used theories, which use conjugates variables. Moreover, we build the action of a charged particle as well, and include the size structure effects, such as tidal deformation, polarization and dissipation in the quasi-static limit. The invariant operators in the action are accompanied by coefficients that encapsulates the properties of the compact object. We match the known coefficients of the effective action from the literature, and point out the unknown ones that are to be derived.

hep-th↗

arXiv2023

Compact Objects from Spontaneous Symmetry Breaking

Gravitational waves from merging compact objects provides the opportunity to explore the properties of black holes and neutron stars in the strong regime of gravity. It is therefore of interest to explore the theoretical model that accurately describes them. Using the coset construction, we build a worldline Effective Field Theory that is derived from symmetry principles, does not involve additional degrees of freedom, and describes the most general compact object allowed in an effective Einstein-Maxwell vierbein theory. Such extended object can be described by its mass, spin, charge and size effects: tides, polarization and dissipation. By recognizing the symmetry breaking pattern, we derive all the covariant building blocks and constraints to build up the relevant invariant operators in the action to all orders. The developed theory elucidates the description of compact objects as an Effective Field Theory.

hep-th↗

arXiv2022

Effective field theory for compact object evolution in binary inspirals

Using the effective field theory framework for extended objects we describe the evolution of spinning compact objects in the late inspiral of the coalescence of a binary, before the plunge and merger, by including leading order corrections due to spin, tides, dissipation and gravitational wave radiation. Our implementation is of particular relevance for probing the stellar structure of compact objects with gravitational wave observations. A spinning compact object in the effective field theory framework is described as a spinning point particle, with its finite size effects encoded in higher order operators in the effective action, operators which have coefficients that encapsulates the internal structure of the star. For the inspiral regime described by non-relativistic general relativity, post-Newtonian corrections to each term of the action can be obtained in a diagrammatic approach, including gravitational radiation effects. Taking into account the aforementioned ingredients of the effective theory, we solve for the dynamics of the inspiral of binary systems using an algorithm for point particle simulations. We extract the gravitational wave as a function of the orbital frequency, input that is generated numerically and then evaluated in the analytic function of the waveform. By performing illustrative numerical experiments of systems that the LIGO-Virgo observatories have already detected, we show the role of the stellar structure and its coefficients in the phase evolution of the waveform, as well as the order in which they arise and the sensitivity required for the gravitational wave observatories to measure them. If these coefficients are to be measured, tight constraints on fundamental physics can be placed.

gr-qc↗

arXiv2019

Probing the Black Hole Merger History in Clusters using Stellar Tidal Disruptions

The dynamical assembly of binary black holes (BBHs) in dense star clusters (SCs) is one of the most promising pathways for producing observable gravitational wave (GW) sources, however several other formation scenarios likely operate as well. One of the current outstanding questions is how these different pathways may be distinguished apart. In this paper we suggest a new multi-messenger observable that can be used to constrain the formation of BBH mergers originating from SCs: the electromagnetic signal from tidal disruptions (TDs) of stars by BBHs. Such TDs will show variability in their light curve from the orbital motion of the disruptive BBHs, and can therefore be used to map the BBH orbital period distribution, and thereby also the dynamical mechanisms that eventually drive the BBHs to merger. Using an analytical approach including General Relativistic effects, we find that the orbital period distribution of BBHs within globular clusters peaks on timescales of days, which we argue is unique to this assembly pathway. We propose that the search for variable TDs in current and future EM transient surveys might be used to constrain the merger history of BBHs in SCs.

astro-ph.HE↗

arXiv2018

Tidal Disruptions of Stars by Binary Black Holes: Modifying the Spin Magnitudes and Directions of LIGO Sources in Dense Stellar Environments

Binary black holes (BBHs) appear to be widespread and are able to merge through the emission of gravitational waves, as recently illustrated by LIGO. The spin of the BBHs is one of the parameters that LIGO can infer from the gravitational wave signal and can be used to constrain their production site. If BBHs are assembled in stellar clusters they are likely to interact with stars, which could occasionally lead to a tidal disruption event (TDE). When a BBH tidally disrupts a star it can accrete a significant fraction of the debris, effectively altering the spins of the BHs. Therefore, although dynamically formed BBHs are expected to have random spin orientations, tidal stellar interactions can significantly alter their birth spins both in direction and magnitude. Here we investigate how TDEs by BBHs can affect the properties of the BH members as well as exploring the characteristics of the resulting electromagnetic signatures. We conduct hydrodynamic simulations with a Lagrangian Smoothed Particle Hydrodynamics code of a wide range of representative tidal interactions. We find that both spin magnitude and orientation can be altered and temporarily aligned or anti-aligned through accretion of stellar debris, with a significant dependence on the mass ratio of the disrupted star and the BBH members. These tidal interactions feed material to the BBH at very high accretion rates, with the potential to launch a relativistic jet. The corresponding beamed emission is a beacon to an otherwise quiescent BBH.

astro-ph.HE↗