Science with the Einstein Telescope: a comparison of different designs
Creators: name: Branchesi, Marica
name: Maggiore, Michele
name: Alonso, David
name: Badger, Charles
name: Banerjee, Biswajit
name: Beirnaert, Freija
name: Belgacem, Enis
name: Bhagwat, Swetha
name: Boileau, Guillaume
name: Borhanian, Ssohrab
name: Brown, Daniel David
name: Chan, Man Leong
name: Cusin, Giulia
name: Danilishin, Stefan L.
name: Degallaix, Jerome
name: De Luca, Valerio
name: Dhani, Arnab
name: Dietrich, Tim
name: Dupletsa, Ulyana
name: Foffa, Stefano
name: Franciolini, Gabriele
name: Freise, Andreas
name: Gemme, Gianluca
name: Goncharov, Boris
name: Ghosh, Archisman
name: Gulminelli, Francesca
name: Gupta, Ish
name: Gupta, Pawan Kumar
name: Harms, Jan
name: Hazra, Nandini
name: Hild, Stefan
name: Hinderer, Tanja
name: Heng, Ik Siong
name: Iacovelli, Francesco
name: Janquart, Justin
name: Janssens, Kamiel
name: Jenkins, Alexander C.
name: Kalaghatgi, Chinmay
name: Koroveshi, Xhesika
name: Li, Tjonnie G. F.
name: Li, Yufeng
name: Loffredo, Eleonora
name: Maggio, Elisa
name: Mancarella, Michele
name: Mapelli, Michela
name: Martinovic, Katarina
name: Maselli, Andrea
name: Meyers, Patrick
name: Miller, Andrew L.
name: Mondal, Chiranjib
name: Muttoni, Niccolò
name: Narola, Harsh
name: Oertel, Micaela
name: Oganesyan, Gor
name: Pacilio, Costantino
name: Palomba, Cristiano
name: Pani, Paolo
name: Pasqualetti, Antonio
name: Perego, Albino
name: Pèrigois, Carole
name: Pieroni, Mauro
name: Piccinni, Ornella Juliana
name: Puecher, Anna
name: Puppo, Paola
name: Ricciardone, Angelo
name: Riotto, Antonio
name: Ronchini, Samuele
name: Sakellariadou, Mairi
name: Samajdar, Anuradha
name: Santoliquido, Filippo
name: Sathyaprakash, B. S.
name: Steinlechner, Jessica
name: Steinlechner, Sebastian
name: Utina, Andrei
name: Broeck, Chris Van Den
name: Zhang, Teng
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: The Einstein Telescope (ET), the European project for a third-generation gravitational-wave detector, has a reference configuration based on a triangular shape consisting of three nested detectors with 10 km arms, where in each arm there is a `xylophone' configuration made of an interferometer tuned toward high frequencies, and an interferometer tuned toward low frequencies and working at cryogenic temperature. Here, we examine the scientific perspectives under possible variations of this reference design. We perform a detailed evaluation of the science case for a single triangular geometry observatory, and we compare it with the results obtained for a network of two L-shaped detectors (either parallel or misaligned) located in Europe, considering different choices of arm-length for both the triangle and the 2L geometries. We also study how the science output changes in the absence of the low-frequency instrument, both for the triangle and the 2L configurations. We examine a broad class of simple `metrics' that quantify the science output, related to compact binary coalescences, multi-messenger astronomy and stochastic backgrounds, and we then examine the impact of different detector designs on a more specific set of scientific objectives.
description: 197 pages, 73 figures. v2: corrections in the part on the sensitivity to stochastic backgrounds. Accepted in JCAP