Extreme recoils: impact on the detection of gravitational waves from massive black hole binaries

Recent numerical simulations of coalescences of highly spinning massive black hole binaries (MBHBs) suggest that the remnant can suffer a recoil velocity of the order of few thousands km/s. We study here, by means of dedicated simulations of black holes build--up, how such extreme recoils could affect the cosmological coalescence rate of MBHBs, placing a robust lower limit for the predicted number of gravitational wave (GW) sources detectable by future space--borne missions (such as LISA). We consider two main routes for black hole formation: one where seeds are light remnants of Population III stars (~10^2 \msun), and one where seeds are much heavier (>~10^4 \msun), formed via the direct gas collapse in primordial nuclear disks. We find that extreme recoil velocities do not compromise the efficient MBHB detection by LISA. If seeds are already massive and/or relatively rare, the detection rate is reduced by only ~15%. The number of detections drops substantially (by ~60%) if seeds are instead light and abundant, but in this case the number of predicted coalescences is so high that at least ~10 sources in a three year observation are guaranteed.Comment: 5 pages, 4 figures, replaced with final versio

Amor y Apoyo: Lecciones de Latinx Families in Nourishing Resilience to First and Second-Generation College Students

The present qualitative study aims to understand how Latino/Hispanic herea er referred to as Latinx, parent involvement is different or similar among first- and second-generation college students in how they experience higher education and how parental education impacts the use of student support services. Hence, supporting Latinx student retention by developing university and parental relationships. Second-generation college students and Latinx parents were unable to be included in the study because of their scarcity or hesitation of participating. Therefore, participants included a convenience sample of six first-generation undergraduate students from a 4-year institution. Semi-structured interviews were conducted to obtain their stories of parental involvement and student involvement. Results suggest that (1) first-generation college students experience a hands-off involvement from parents, however, they enjoyed the freedom this brought, (2) Latinx parents might have a misunderstanding of college student identity, and (3) students expressed a desire to have their parents learn about and understand mental health. Implications of findings include universities creating more resources to support Latinx students’ mental health, as well as earlier school outreach for Latinx parent involvement to better inform them about the college lifestyle

Adaptive dynamic path re-planning RRT algorithms with game theory for UAVs

The main aim of this paper is to describe an adaptive re-planning algorithm based on a RRT and Game Theory to produce an efficient collision free obstacle adaptive Mission Path Planner for Search and Rescue (SAR) missions. This will provide UAV autopilots and flight computers with the capability to autonomously avoid static obstacles and No Fly Zones (NFZs) through dynamic adaptive path replanning. The methods and algorithms produce optimal collision free paths and can be integrated on a decision aid tool and UAV autopilots

N electrons in a quantum dot: Two-point Pade approximants

We present analytic estimates for the energy levels of N electrons (N = 2 - 5) in a two-dimensional parabolic quantum dot. A magnetic field is applied perpendicularly to the confinement plane. The relevant scaled energy is shown to be a smooth function of the parameter \beta=(effective Rydberg/effective dot energy)^{1/6}. Two-point Pade approximants are obtained from the series expansions of the energy near the oscillator ($\beta\to 0$) and Wigner ($\beta\to\infty$) limits. The approximants are expected to work with an error not greater than 2.5% in the entire interval $0\le\beta < \infty$.Comment: 27 pages. LaTeX. 6 figures not include

Automorphisms of p-local compact groups

Peer reviewedPostprin

Two and three electrons in a quantum dot: 1/|J| - expansion

We consider systems of two and three electrons in a two-dimensional parabolic quantum dot. A magnetic field is applied perpendicularly to the electron plane of motion. We show that the energy levels corresponding to states with high angular momentum, J, and a low number of vibrational quanta may be systematically computed as power series in 1/|J|. These states are relevant in the high-B limit.Comment: LaTeX, 15 pages,6 postscript figure