Science with the Einstein Telescope: a comparison of different designs

Marica Branchesi , Michele Maggiore , David Alonso , Charles Badger , Biswajit Banerjee , Freija Beirnaert , Swetha Bhagwat , Guillaume Boileau (1) , Ssohrab Borhanian , Daniel David Brown , Man Leong Chan , Giulia Cusin (2) , Stefan L Danilishin , Jerome Degallaix (3) , Valerio de Luca , Arnab Dhani , Tim Dietrich , Ulyana Dupletsa , Stefano Foffa , Gabriele Franciolini , Andreas Freise , Gianluca Gemme , Boris Goncharov , Archisman Ghosh , Francesca Gulminelli (4) , Ish Gupta , Pawan Kumar Gupta , Jan Harms , Nandini Hazra , Stefan Hild , Tanja Hinderer , Ik Siong Heng , Francesco Iacovelli , Justin Janquart , Kamiel Janssens (1) , Alexander C Jenkins , Chinmay Kalaghatgi , Xhesika Koroveshi , Tjonnie G.F Li , Yufeng Li , Eleonora Loffredo , Elisa Maggio , Michele Mancarella , Michela Mapelli , Katarina Martinovic , Andrea Maselli , Patrick Meyers , Andrew L Miller , Chiranjib Mondal (4) , Niccolò Muttoni , Harsh Narola , Micaela Oertel (5) , Gor Oganesyan , Costantino Pacilio , Cristiano Palomba , Paolo Pani , Antonio Pasqualetti , Albino Perego , Carole Périgois , Mauro Pieroni , Ornella Juliana Piccinni , Anna Puecher , Paola Puppo , Angelo Ricciardone , Antonio Riotto , Samuele Ronchini , Mairi Sakellariadou , Anuradha Samajdar , Filippo Santoliquido , B.S Sathyaprakash , Jessica Steinlechner , Sebastian Steinlechner , Andrei Utina , Chris van den Broeck , Teng Zhang

1 ARTEMIS - Astrophysique Relativiste Théories Expériences Métrologie Instrumentation Signaux
2 IAP - Institut d'Astrophysique de Paris
3 LMA - Laboratoire des matériaux avancés
4 LPCC - Laboratoire de physique corpusculaire de Caen
5 LUTH (UMR_8102) - Laboratoire Univers et Théories

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.

Keywords: detector; design; frequency; low; binary; coalescence; compact; high; family; 3; background; stochastic; geometry; triangulation; interferometer; Einstein Telescope; gravitational radiation detector; observatory; network; cryogenics; temperature

Domains: General Relativity and Quantum Cosmology [gr-qc]

Marica Branchesi, Michele Maggiore, David Alonso, Charles Badger, Biswajit Banerjee, et al.. Science with the Einstein Telescope: a comparison of different designs. JCAP, 2023, 07, pp.068. ⟨10.1088/1475-7516/2023/07/068⟩. ⟨hal-04062419⟩