WGCPcall20180209 - Revision history

HelviWitek at 16:11, 27 August 2018

2018-08-27T16:11:48Z

HelviWitek at 15:27, 27 August 2018

2018-08-27T15:27:36Z

159.92.238.8: /* Minutes */

2018-03-19T18:23:59Z

‎Minutes

Noncct katyclough: /* Call: April 2018 */

2018-03-19T18:00:55Z

‎Call: April 2018

Noncct katyclough: /* Call: March 19th, 2018 */

2018-03-19T18:00:18Z

‎Call: March 19th, 2018

Noncct katyclough: /* Previous calls */

2018-03-19T17:59:24Z

‎Previous calls

Noncct katyclough: /* Previous calls */

2018-03-19T17:58:47Z

‎Previous calls

Noncct katyclough: /* Meeting agenda */

2018-03-19T17:56:39Z

‎Meeting agenda

193.136.197.251: /* Call: March, 19th 2018 */

2018-03-15T09:54:27Z

‎Call: March, 19th 2018

193.136.197.251: /* Call: March 2018 */

2018-03-15T09:54:10Z

‎Call: March 2018

@@ Line 1: / Line 1: @@
 =Next call=
 == Call: 1 October 2018 ==
 === Meeting Agenda ===
@@ Line 13: / Line 6: @@
 = Previous calls =
 == Call: 25 June 2018 ==

@@ Line 1: / Line 1: @@
 =Next call=
 == Call: 23 April 2018 ==
 === Meeting Agenda ===
-* [KC] Intro to GRChombo (http://www.grchombo.org/)
+* [KC] introduction to GRChombo (http://www.grchombo.org/)
 == Call: March 19th, 2018 ==
@@ Line 12: / Line 68: @@
 === Minutes ===
 Participants: Sante Carloni, Katy Clough, Michele Grasso, Bishop Mongwane, Erik Schnetter, Daniele Vernieri, Helvi Witek
 * Timing for regular meeting
 ** Agreed that we will aim to meet once a month on Mondays at 4.30pm GMT / 5.30pm CET time
 ** Agreed that having a 20 minute discussion on a specific topic at each call is a good idea to give a focus to the call
@@ Line 30: / Line 84: @@
 == Call: February 9th, 2018 ==
 === Meeting agenda ===
 * [HW] introduction and scope of the working group
@@ Line 36: / Line 89: @@
 === Minutes ===
 Participants:
-Eloisa Bentivegna,
+Eloisa Bentivegna, Sante Carloni, Katy Clough, Isabel Cordero, Michele Grasso, Daniele Vernieri, Helvi Witek
 * Introduction

@@ Line 13: / Line 13: @@
 === Minutes ===
-Participants: Sante Carloni, Katy Clough, Michele Grasso, Erik Schnetter, Daniele Vernieri, Helvi Witek
+Participants: Sante Carloni, Katy Clough, Michele Grasso, Bishop Mongwane, Erik Schnetter, Daniele Vernieri, Helvi Witek
 * Timing for regular meeting

@@ Line 1: / Line 1: @@
-== Call: April 2018 ==
+=Next call=
 === Meeting Agenda ===
 * [KC] Intro to GRChombo (http://www.grchombo.org/)

←Older revision		Revision as of 18:00, 19 March 2018
Line 1:		Line 1:
−	~~== Call: March 19th, 2018 ==~~
−	~~=== Meeting agenda ===~~
−	* [DV] introduction to Horndeski theories
−	* [HW] regular meeting time
−
−	~~=== Minutes ===~~
−
−	~~Participants: Sante Carloni, Katy Clough, Michele Grasso, Erik Schnetter, Daniele Vernieri, Helvi Witek~~
−
−	* Timing for regular meeting
−
−	** Agreed that we will aim to meet once a month on Mondays at 4.30pm GMT / 5.30pm CET time
−	** Agreed that having a 20 minute discussion on a specific topic at each call is a good idea to give a focus to the call
−	** Next meeting will be on 23rd April, with 20 minute discussion on GRChombo numerical relativity code
−
−	* Horndeski theories
−	** DV gave an introduction to Horndeski theories, which are the most general theories with an additional scalar field leading to second order field equations.
−	** The original Horndeski paper was published in 1973 but the theory was rediscovered in 2010 in the the equivalent context of Galileons, after which it became more popular in research
−	** The field equations can be simplified (a little!) by writing them in terms of 4 arbitrary functions of the field phi and the kinetic term X.
−	** Covers a number of common modified gravity theories - f(R), Brans-Dicke, Gauss-Bonnet.
−	** Recent measurements of GWs have been used to show (PRL 119 251302, 2017) that, given that the speed of propagation of GWs is c (to very high precision), several terms in the most general action must be set to zero. This may rule out the Vainstein screening mechanism.
−	** Some work is being done to investigate the well-posedness of the equations, (see https://arxiv.org/abs/1710.10155, https://arxiv.org/pdf/1705.04370.pdf), which is crucial for their numerical formulation and evolution, but so far they have only been shown to be weakly hyperbolic. This may, however, be due to issues around gauge choices.
−
	== Call: April 2018 ==		== Call: April 2018 ==
	=== Meeting Agenda ===		=== Meeting Agenda ===

@@ Line 27: / Line 27: @@
 = Previous calls =
 == Call: February 9th, 2018 ==
@@ Line 63: / Line 87: @@
 ** next meeting in the beginning of March; Helvi will create doodle closer to the date
 ** please consider attending the workshop [http://benasque.org/2018relativity/ ``Numerical relativity beyond GR''] in Benasque/ Spain, 3-9 June 2018

←Older revision		Revision as of 17:58, 19 March 2018
Line 63:		Line 63:
	** next meeting in the beginning of March; Helvi will create doodle closer to the date		** next meeting in the beginning of March; Helvi will create doodle closer to the date
	** please consider attending the workshop [http://benasque.org/2018relativity/ ``Numerical relativity beyond GR''] in Benasque/ Spain, 3-9 June 2018		** please consider attending the workshop [http://benasque.org/2018relativity/ ``Numerical relativity beyond GR''] in Benasque/ Spain, 3-9 June 2018
		+
		+	== Call: March 19th, 2018 ==
		+	=== Meeting agenda ===
		+	* [DV] introduction to Horndeski theories
		+	* [HW] regular meeting time
		+
		+	=== Minutes ===
		+
		+	Participants: Sante Carloni, Katy Clough, Michele Grasso, Erik Schnetter, Daniele Vernieri, Helvi Witek
		+
		+	* Timing for regular meeting
		+
		+	** Agreed that we will aim to meet once a month on Mondays at 4.30pm GMT / 5.30pm CET time
		+	** Agreed that having a 20 minute discussion on a specific topic at each call is a good idea to give a focus to the call
		+	** Next meeting will be on 23rd April, with 20 minute discussion on GRChombo numerical relativity code
		+
		+	* Horndeski theories
		+	** DV gave an introduction to Horndeski theories, which are the most general theories with an additional scalar field leading to second order field equations.
		+	** The original Horndeski paper was published in 1973 but the theory was rediscovered in 2010 in the the equivalent context of Galileons, after which it became more popular in research
		+	** The field equations can be simplified (a little!) by writing them in terms of 4 arbitrary functions of the field phi and the kinetic term X.
		+	** Covers a number of common modified gravity theories - f(R), Brans-Dicke, Gauss-Bonnet.
		+	** Recent measurements of GWs have been used to show (PRL 119 251302, 2017) that, given that the speed of propagation of GWs is c (to very high precision), several terms in the most general action must be set to zero. This may rule out the Vainstein screening mechanism.
		+	** Some work is being done to investigate the well-posedness of the equations, (see https://arxiv.org/abs/1710.10155, https://arxiv.org/pdf/1705.04370.pdf), which is crucial for their numerical formulation and evolution, but so far they have only been shown to be weakly hyperbolic. This may, however, be due to issues around gauge choices.

@@ Line 3: / Line 3: @@
 * [DV] introduction to Horndeski theories
 * [HW] regular meeting time
 == Call: April 2018 ==