<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Dear all,<div class=""><br class=""></div><div class="">I would like to propose the inclusion of FLRWSolver in the Einstein Toolkit.</div><div class=""><br class=""></div><div class="">FLRWSolver is a thorn for cosmological initial conditions. It provides initial data for a flat, matter-dominated (dust), Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetime with small (linear) perturbations.</div><div class="">Both simplified “toy” initial data and realistic perturbations are currently supported. The latter consists of Gaussian-random fluctuations to the background drawn from a user-provided matter power spectrum. The user therefore only needs to provide the power spectrum of density fluctuations and specify the FLRW background characteristics to perform a realistic cosmological simulation of nonlinear structure formation using the ET. Numerical relativity has proven an extremely useful tool to study general relativistic effects in nonlinear cosmology, and the ET + FLRWSolver provides a useful framework for such studies (see, e.g. <a href="https://arxiv.org/abs/1807.01711" class="">https://arxiv.org/abs/1807.01711</a>).</div><div class=""><br class=""></div><div class="">FLRWSolver has been used in several publications, and has been public for ~2 years at this repository: <a href="https://github.com/hayleyjm/FLRWSolver_public" class="">https://github.com/hayleyjm/FLRWSolver_public</a>, and already has 4-6 users (as far as I know).</div><div class=""><br class=""></div><div class="">If you are already using FLRWSolver, may be interested in using it in the future, or are just interested in seeing it as a part of the ET, please comment on this enhancement ticket:</div><div class=""><a href="https://bitbucket.org/einsteintoolkit/tickets/issues/2549/inlcude-flrwsolver-in-et" class="">https://bitbucket.org/einsteintoolkit/tickets/issues/2549/inlcude-flrwsolver-in-et</a></div><div class=""><br class=""></div><div class="">I am working towards including FLRWSolver in the next release, but if there are any feedback/suggestions in the meantime then please don’t hesitate to reply/contact me. I’m more than happy to improve/extend FLRWSolver (and even delay to the following release if need be) if it’s in the best interest of the community.</div><div class=""><br class=""></div><div class="">Best wishes,</div><div class="">Hayley</div><div class=""><br class=""><div class="">
<div dir="auto" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div dir="auto" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div>----</div><div><br class=""></div><div>Hayley Macpherson</div><div><br class=""><a href="mailto:hayleyjmacpherson@gmail.com" class="">Email: hayleyjmacpherson@gmail.com</a><br class="">Pronouns: she/her/hers<br class=""><br class="">Office: my house (usually B1.23)<br class="">Centre for Theoretical Cosmology<br class="">DAMTP, University of Cambridge <br class="">Wilberforce Road<br class="">CB3 0WA Cambridge<br class="">United Kingdom</div></div></div>
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