ET - WG 4
CARDIFF MEETING

MINUTE 25 Mar 2009
=====================


@Cardiff
Nils Andersson
Henk Yan Bulten
Ronny Nawrodt
Siong Heng
Patrick Sutton
Chris Van Den Broeck
James Clark
Tomasz Bulik
B.S. Sathyaprakash
Jonathan Gair
Gareth Jones
Leone B. Bosi

@Telephone
Badri Krishnan
Jocelyn Read
Eric Chassande-Mottin
Michele Punturo
Tania Regimbau
S. Barback
Sascha Husa
Miquel Trias
Eric Chassande-Mottin
Harald Luck
John Veitch
Palomba Cristiano
Richard O?Shangnessy
Alex Diez
Stefan Hild
Llucia Sancho
Jo van den Brand
Alicia Sintes


Sathya: Opening the discussion about the ET document, budget and resources. 


@Tania Talk

- Clarification about the eccentricity. Tania considers the eccentricity not important. An important issue is how the eccentricity affects the background.
- It has been asked to clarify what has been show in slide 12.


@Bulik Talk

-About the rate; It has been pointed that BBH originated by population III stars, having mass >100Ms are interesting.
- Sathya: Evolution of binary rate vs red-shif is an important information that has to be shared inside our collaboration. Such data are useful and at the base for other analysis. Thus, it has been requested, if it is possible, to create a webpage inside ET-working-area or to upload a file with such information. This is an important effort.

 --> Tania: provide ascii file


@Hild Talk

- ET-B sensitivity can be downloaded from WG3 workarea, where these is a matlab file.
- Sathya requests to have an announcement when there are sensitivity updates.
- @1Hz still missing for a factor 50 far from the target sensitivity.

Important questions to WG4:

1) @Slide 10: Inputs from WG4 on sensitivity trade-off. In particular: Can we trade-off a poor
sensitivity below 3 Hz, by improved sensitivity around 10 Hz? 
Leone: 	"Maybe have significative more energy above 10Hz can be mode important than have better sensitivity at 1Hz"
Patrick: "Longest template could provide a better sky resolution"
Leone: 	"Simulation seems to say that the information given by longest template doesn?t provide improved sky resolution"
Chris:   "confirm the result"
   
2) @Slide 11: Is there any problem on splitting the detection in 2-3  detectors ("xilophone"). In Slide 12 there is an example with 2 detector, having the crossover frequency close to 20Hz.

3) Are violin modes a problem for the WP4 point of view? 
Punturo: "the Df is of the order of mHz, hence they are not a problem." In usual DA tasks violin modes are not a problem


@Sathya talk

- Eric: "All this study consider to have EM signature, but the sky resolution could be not good"
- Sathya: "Consider that we can have Gamma-ray burst"


@ Krishnan

- Crab e vela are the really interesting objects, because we have an EM information
- The actual computational requirements are about 17GFlops. In ten years it will increase of a factor 10.


- It takes place a discussion on Vision Document and tasks assignation. 

- It has been important the point about the big question (Nils) and how ET can help our theoretical understanding of relativistic dynamics and nuclear physics (Leone/Nils). 
o Are black holes described by the Kerr metric?
o What is the state of matter extreme densities?
o Strong field tests of general relativity
o What is the nature of the Universe?
o How are black holes assembled?
o Cosmological evolution of compact object populations?
o How can ET help our theoretical understanding of relativistic dynamics?
o ...

This is important, remarking that ET main goal is not the detection but the possibility to measure and make "broadband"physics from/with GW. 

@Leone talk: He propose to consider SNR higher than 8 when we estimate sources/rates/etc.. on the context of ET science. This is important to affirm with high probability that what we are seeing is a GW. Maybe SNR 10 or more. This has been considered not important. He propose also the realization of a table/database where organize sources characteristics/ET science opportunity lists. This has been considered interesting.