Cosmology and Particles
Working Group: Cosmology and Particles
Date Approved: December 4th, 2017
Leads: Eloisa Bentivegna, Helvi Witek
Approval date: ET call on 2017-11-27
Background: The study of relativistic effects and strong-field dynamics is playing an increasingly important role in many disciplines related to, but not necessarily overlapping with, gravitational-wave astronomy. The full numerical integration of Einstein’s equation has now been adopted to describe structure formation in the late Universe, high-energy processes near black holes, gravitational-wave emission by exotic objects, and many other phenomena. However, numerical implementations of extensions to GR -- be it in the form of additional fields serving as dark matter candidates, more involved extensions motivated by quantum gravity paradigms or novel initial conditions for inflation -- are still scarce. Many of these effects are expected to be testable with advanced LIGO/Virgo or the space-based LISA mission. In order to match theory with observations it is crucial to prepare the necessary waveform models, which is one of the goals of this working group.
This Working Group should serve as the first arena to discuss extensions of Numerical Relativity towards new physical applications and their implementation in the Einstein Toolkit, enabling the modelling of these spacetimes beyond the traditional canons of GW-related NR. Given the exploratory character of many of these applications, the discussion will include not only algorithmic and infrastructural aspects, but also foundational issues connected to the physical and mathematical traits of the theories involved (such as how to best formulate the constitutive equations, construct initial data, define observables, and so on).
Activities: The Working Group will hold a monthly or bimonthly brainstorming call. Practical developments arising from the discussions may be subsequently formalized as Development Teams and attached to this WG’s activities. The calls may also contain short seminars. The development of an interface to the many experiments and observational missions within the WG’s scope should be among the top priorities.
Milestones: The main objective of this Working Group is that of collecting all the interested parties in a single community, give it an official structure, promote brainstorming and knowledge-sharing in this vast new field, and provide a public interface to the growing number of non-GW relativists who are turning to the Einstein Toolkit to extend the reach of their investigations in their respective fields.
Deliverables: This WG will deliver a yearly document, representing the Group’s outlook on the year’s developments in the field such as major publications, conferences, code releases, grant awards and their possible ramifications, the topics discussed during the calls, and any other issue of interest. This document will be the standard reference both for existing ETers looking to join new projects and for new members from other areas of Theoretical Physics where the ET may be employed. Furthermore, we expect new add-ons to the Einstein Toolkit as deliverables of this working group. Ensuring the quality and and performance of these thorns, as well as cross-checking new code, will be part of the WG’s responsibility.
Engagement: New members can join the working group by subscribing to the mailing list firstname.lastname@example.org.
Working group calls
Link for the calls: https://hangouts.google.com/hangouts/_/tce4j4gzcfcormnadoauiqcvg4e