Cosmo-torun

cosmo-torun@cosmo.torun.pl

328 discussions

wtorek 25.05.2006 13.00g @KRA: prezentacji/dyskusji nBDM
by Boud Roukema 24 Apr '06

24 Apr '06

Cześć wszystkim, Jutro wtorek (25.04.2006r) o 13.00g Łukasz i Agnieszka będą wyjaśnić gdzie są na temacie nie-barionowej ciemniej materii. :) Miejsce: KRA (albo sala seminarium albo mój biuro) Będzie więcej stylu warsztat niż ,,wstęp dla początkowych", więc osoby, którze zapomniali temat (lub jeszcze nie znają temat) są polecane czytać podstawy: http://cosmo.torun.pl/cgi-bin/twiki/view/Cosmo/NonBaryonicDarkMatter na jutrze boud

1 0

Britannica vs. Wikipedia
by Andrzej Marecki 30 Mar '06

30 Mar '06

Which source is more error prone: Britannica or Wikipedia? Read: http://www.nature.com/nature/journal/v440/n7084/full/440582b.html -- a.m.

2 1

[Cosmo-pl] WMAP 3yr data - Omega_tot \approx 1.010-1.015 :))))) (fwd)
by Boud Roukema 17 Mar '06

17 Mar '06

hi everyone, i don't know if everyone on cosmo-torun is on cosmo-pl. Anyway, i sent the following to cosmo-pl. pozdr boud > > > ---------- Forwarded message ---------- > Date: Fri, 17 Mar 2006 16:25:42 +0100 (CET) > From: Boud ... > To: cosmo-pl at ... > Subject: [Cosmo-pl] WMAP 3yr data - Omega_tot \approx 1.010-1.015 :))))) > > Witam cosmo-pl, > > The 3-year WMAP data is now available: > http://lambda.gsfc.nasa.gov/product/map/dr2/ilc_map_get.cfm > > As expected from the Poincare Dodecahedral Space analyses, e.g. > http://arxiv.org/abs/astro-ph/0310253 Luminet et al. > http://arxiv.org/abs/astro-ph/0402608 Toruń > http://arxiv.org/abs/astro-ph/0412569 Aurich Lustig Steiner > http://arxiv.org/abs/astro-ph/0503014 Gundermann > http://arxiv.org/abs/astro-ph/0504656 Aurich Lustig Steiner > > the estimates of Omega_total remain in the range 1.010-1.020. :)))) > > Spergel et al find: > > http://lambda.gsfc.nasa.gov/product/map/dr2/pub_papers/threeyear/parameters… > > Omega_tot = > 1.015 (+0.020,-0.016) WMAP-3yr + SNLS (supernova legacy survey) > 1.010 (+0.016,-0.009) WMAP-3yr + HST key project on H_0 > > No matter how hard people try to combine different data sets, it seems > that nobody can get Omega_tot much closer to 1.000 (except by assumption). > > In the conclusion, section 9, page 61 of Spergel et al., you'll see > that after people like me have repeated ad infinitum in many, many > seminars etc that WMAP does not imply a flat Universe, it only > implies a "nearly flat Universe", finally, Spergel et al. have started > using this expression: > > "The WMAP data are consistent with nearly flat universe". > > :) > > Anyway, hopefully in the next week, i and the other people who have > volunteered ;) to help organise a small, "polish cosmology" > workshop/meeting in Toruń, probably in May, will send out a > "pre-registration" announcement... > > > pozdr > boud > > _______________________________________________ > Cosmo-pl mailing list > Cosmo-pl at cosmo.torun.pl > http://cosmo.torun.pl/mailman/listinfo/cosmo-pl >

1 0

wmap2
by Bartosz Lew 16 Mar '06

16 Mar '06

hi all, the wmap 2nd year data finally are abaut to be released - today :] http://www.bautforum.com/showthread.php?t=23857&page=10 pozdr. bartek

1 0

money (FNP)
by Boud Roukema 23 Feb '06

23 Feb '06

hi cosmo-torun, Ajk recommends that we consider looking at the many different sorts of funding possible from the FNP: http://www.fnp.org.pl/ Two applications made to FNP last year for Eastern European cosmology visitors to spend some time here were rejected. pozdr boud

1 0

the shape of the universe (fwd)
by Boud Roukema 20 Feb '06

20 Feb '06

hi everyone, We have a media question :). i don't want to spam people, so anyone interested, please respond on cosmo-media@ ... rather than cosmo-torun. Below are my proposed "compact" answers. Any corrections before i respond "officially"? Remember the number one rule of the dependent media: "anything you say may and will be misquoted against you". Which is why having this on the cosmo-media archive will at least, in principle, provide some defence... i don't know what time frame the journalist has in mind - but presumably the sooner the better for any answers. IMHO probably a day or two should be OK. pozdr boud > ---------- Forwarded message ---------- > Date: Wed, 15 Feb 2006 23:38:49 +0100 > From: t.rozek at fz-juelich.de > To: boud at astro.uni.torun.pl > Subject: the shape of the universe > > Dear Sir, > > I'm a physicist and scientific writer. Within the new project of Axel Springer publishing house (editor of Newsweek in Poland and Die Welt in Germany) in Poland I would like to invite you to the discussion about the shape of the universe. > > As I know scientific group you are the leader, in 2004 went public with the information that in the microwave background radiation picture there are some indications, that our universe has a shape of dodecahedron. > > Questions I'm asking you are the same like these I have sent to other expert in this field. I will not hide, that his opinion about the shape of the universe is different than your. > > I will be pleased to get from you compact answers to questions which are listed below. Please keep in mind that new Axel Springer daily will be addressed to nonspecialists in physics or astronomy. > > Let me thank you in advance for time you will spend to answer my questions. I'm looking forward to your respond. > > With the best regards > Tomasz Rozek ---------------------------------------------------------------------- > Questions: > 1. Analysis of the microwave background radiation are the only way > - I guess - to collect information about the shape of the > universe. Isn't it risky to draw conclusions resulting from only one > experiment ? Yes, it is risky to draw conclusions from only one experiment. We expect other scientists to read our paper carefully and make their own analyses of microwave background and other data. The most independent test of our work will be testing the prediction that the average, total density parameter of the Universe, including ordinary matter, dark matter and dark energy together, should be about 0.9% to 1.1% higher than the density which would make the Universe perfectly flat ("flat" means that Pythagoras' Theorem is true). This type of test is highly independent of our analysis method. > 2. Why this is commonly believed, that data from WMAP probe, brought > down the concept of flat and infinite universe ? The flat and infinite universe model is still consistent with the WMAP data. It is not the best model, but it is still consistent with the data and most observational cosmologists still take it as the best approximation we have. Please remember, however, that no theoretical cosmologists take the flat and infinite model as a serious model of the entire Universe - it is only treated as a limiting case inside the observable sphere. > 3. There are many ideas concerning the shape of the universe. Maybe > it is like a sphere, cylinder, funnel, but it can also be like bell, > horn or dodecahedron. Why do you claim that space is > dodecahedron-like ? We don't. The first misunderstanding is that "shape" means the shape of *space itself*, not the shape of *space inside of space*. Our intuition is developed to think of objects inside of three-dimensional, Euclidean, infinite space. In order to understand what is meant by the shape of the Universe, you first need to develop a method of thinking about the shape of space itself. A good place to start would be http://pl.wikipedia.org/wiki/Ksztalt_Wszechswiata . One example of a shape of space itself is a space with the name "Poincare dodecahedral space" (PDS). One "ordinary" shape, inside of space, which helps to think about the PDS, is the dodecahedron. The second misunderstanding is that so far our group only claims to have a "hint" of that the shape of space is the PDS. Our analysis follows that by Jean-Pierre Luminet's group. Ralf Aurich's group and Jesper Gundermann have also found similar (though not exactly identical) results. > 4. What are the errors or defects of the idea of horn-like space ? None as far as I am aware of. > 5. Could you in the very easy way explain the expression, that space > has a shape ? Imagine that space only has two dimensions, instead of three. Now we can use our existing intuition about three-dimensional space to imagine many different possible two-dimensional spaces inside of three-dimensional space. In this way, we use one dimension as a purely psychological dimension. It's used by our brain, but has no physical meaning for the two-dimensional space we're thinking about. Of course, real space has three dimensions (we can ignore the time dimension for discussion of "the shape of space"), so if you can now start thinking in four dimensions, then you can use the fourth dimension as a psychological dimension and think of differently shaped spaces, each having three dimensions. > 6. Do efforts to establish a shape of the universe have any > practical meaning or you are doing that just to know ? Both. It is practical to know the shape of a footpath or a tree or a mountain or an atom or a molecule, so it is practical to know the shape of the Universe. But it is also good to knowing the shape of a work of Picasso or a beautiful woman or man, even if this has no practical use. > 7. Did universe have a beginning, and ones will have the end ? The standard hot big bang model is very well established, and this model has a limiting time we can call "time equals zero". If we start today and think backwards towards "time equals zero", then our model of the Universe becomes more and more speculative as we get towards "time equals zero". So it is more realistic to say that we have a standard model which goes *towards* having a beginning rather than saying the Universe actually "had" a beginning. However, theoretical cosmologists have some ideas of universe models extending earlier than "time equals zero". ----------------------------------------------------------------------

3 9

120 cell
by Jeff Weeks 06 Feb '06

06 Feb '06

Dear Boud et al., You intuition is correct -- there are some additional in-between layers. The attached images show layers 1 through 5. Layers 6 through 9 are of course symmetrical as you work your way towards the south pole. Note that the cells in layer 5 sit "vertically" with respect to the equatorial hyperplane (i.e. they're orthogonal to the equatorial hyperplane) which is why they appear flat in the attached image (each dark blue hexagon is the 2D shadow of a 3D cell when you project from 4D space to 3D space). Anyhow, here's the accounting: layer 1 1 layer 2 12 layer 3 20 layer 4 12 layer 5 30 layer 6 12 layer 7 20 layer 8 12 layer 9 1 ----------- total 120 Note that all numbers are "dodecahedal numbers", respecting the dodecahedral symmetry of the whole construction. The 120-cell is quite beautiful, isn't it? Best wishes to all of you, Jeff

1 0

MG11 - Topology of the Universe (fwd) (and PDS - how many tiles?)
by Boud Roukema 06 Feb '06

06 Feb '06

hi everyone, The following is self-explanatory - you can reply to Marek directly - here is his email in antispam format (this list is publicly archived so better not write people's email addresses in ways that robots can read them): Marek.Demianski at fuw edu pl > ---------- Forwarded message ---------- > Date: Mon, 6 Feb 2006 15:02:38 +0100 (CET) > From: Marek Demianski > Subject: MG11 - Topology of the Universe > > > Dear Colleague, > > I have been asked to organize a parallel session on "Topology of the > Universe" at the XI Marcel Grossmann Meeting in Berlin, July 23 > - 29, 2006. If you are planing to attend the meeting and would like to > present a contribution at this session please let me know. Please spread this > information among your friends and collaborators. > > More information about the Meeting (and on line registration) you can > find at www.icra.it/MG/mg11. Please register by May 31 > to save 50EURO on the conference fee. > > Sincerely yours, > Marek Demianski BTW: i have a question on PDS (Poincare Dodecahedral Space) intuition which someone might be able to answer. A tiling of S^3 by the PDS has 120 copies of the PDS. If we think of this tiling starting from "here" at the "North Pole" (sorry Marcelo, this is North bias ;) (image 1) and we "stick" a copy (image 2) of the PDS next to itself along a North-Pole-South-Pole axis (e.g. X), and then moving along the X axis, we stick another copy (image 3) next to image 2, and then another and so on, then it seems to me that image 6 covers the "South Pole" and is the "antipode" copy of image 1. In other words, the "distance" between the poles is 5 copies of the FD. This allows an easy order of magnitude check on the total number of copies, since the "radius" of one hemi-hypersphere is 2.5 "copies", so that the total volume is roughly (using flat space arithmetic): 2* (4\pi/3) (2.5)^3 \sim 2* 2^2 * (5/2)^3 = 5^3 = 125 which is a good approximation to 120. (AFAIR, Jeff Weeks showed me how to do this - this is not original.) Now for my question: We have 6 "layers": North pole - 1 FD layer 2 - 12 FD's layer 3 - n FD's layer 4 - n FD's layer 5 - 12 FD's South pole - 1 Clearly layer 3 or 4 has more than 12 copies, there are some spaces that need to be filled. But the value required for the total to be 120, i.e. n= 47, is an odd number. Intuition says that everything should be even and symmetric. Can someone give a nice intuitive explanation for why n is odd and why this 12-symmetry is broken? Maybe a nice diagram? In fact, i have a partial answer: it seems to me there are some in-between layers, which we might call 2.5 and 4.5 and i guess also 3.5. But it's difficult for me to imagine them, and it's still difficult for me to imagine how the 12-symmetry is broken. It would be nice if someone had a nice diagram or intuitive explanation of how the 12-symmetry is broken. Going to a 122 tiling would save the tiling symmetry, but intuition says that 120 is better than 122. On the other hand, 2 * (1 + 12 + 48) = 122 seems simpler in terms of tiling symmetry. In the Nature paper, 120 is quoted: http://arxiv.org/abs/astro-ph/0310253 (After all, we *have* made a few minor mistakes in the past in our subject - e.g. when we said that there were uncountably many negatively curved 3-manifolds, and eventually, at MG IX (?), Jeff explained and showed us that the number was countably infinite - the classification is complicated and unfinished, but the number is countable.) cheers boud

1 0

Re: Podreczniki
by Boud Roukema 31 Jan '06

31 Jan '06

witam On Tue, 31 Jan 2006, Karolina Wojtkowska wrote: > > Wszystkich pracowników Centrum prosze o przeslanie listy podrecznikow do > wykladów / ćwiczeń przez siebie prowadzonych. Jeśli to znacze, że Biblioteka może kupić kilka kopii książki, że traktuję jak podstawowy dla mój wykładu, wtedy polecam kupić 5-10 kopii Liddle'a po polsku: http://www.proszynski.pl/asp/fiszka.asp?ksiazka_id=1687 Jest nie drogi, więc nie widzę problem kupić kilka. W tej chwili wydaje mi się, jest tylko jeden w CA-UMK - ,,w katalogowaniu", plus jeden w BG: http://lx.bu.uni.torun.pl/cgi-bin/BG/Z2Wumk/z2w_f.pl?kl=23062-1045663056&di… pozdr boud

1 0

sprawozdanie 2005
by Boud Roukema 30 Jan '06

30 Jan '06

czesc sorry, probably by the time you read this, the sprawozdanie meeting will already be over :P Anyway, here it is - only the first few slides are for the 10 minute presentation, of course - the other pages are "extra in-depth material" which you've probably already seen anyway. http://cosmo.torun.pl/~boud/spraw05pp4.pdf The interesting thing is that there are more and more of us IMHO :) we're starting to get near the numbers necessary to making research be more and more motivating, i.e. a real cosmology research group... :) Of course, let's see if we get our projects into good shape and publishable.... pozdr boud

1 0

biblioteka
by Boud Roukema 26 Jan '06

26 Jan '06

Cześć wszystkim, W tej chwili mamy prośbę dać opinii o zakup między ,,standardowymi" książki konferencowych, każdy kosztują coś jak 100-200 euro, dla bibliotece CA-UMK. Ja znakowałem ksziążki, które mi oglądają jak użyteczny dla badania ekstragalaktycznego-kosmologicznego. Ale w ogóle, moglibyśmy prosić do Katarzyny zrobić nowy zakupy książki kosmologiczny, które jeszcze brakują. Chyba ostatnio raz, że zrobiliśmy, było 3 lata temu. Strona www z listę co znalezliśmy (czy kupiliśmy) ostatnio raz jest tu (na starym wiki, tzw. ,,zwiki"): http://adjani.astro.uni.torun.pl:9673/zwicky/BibliotekaCosmo Jeśli ktoś chce to kopiować/edytować do ,,nowym" wiki (twiki), bardzo proszę: http://cosmo.torun.pl/cgi-bin/twiki/view/Cosmo/BibliotekaCosmo Mój pryorytet w tej chwili dla książki byłoby raczej dla teksty podstawowych dla studentów - np kilka Peebles 1993 ,,zbiory" ? W tej chwili mamy dwie ,,czyt" (chyba to znacze, czytać na miejscu?): http://lx.bu.uni.torun.pl/cgi-bin/BG/Z2Wumk/z2w_f.pl?kl=23062-1045663056&di… I UMK w ogóle ma *wiele* Schutz: nowa edycja 2002 - 7 kopii http://lx.bu.uni.torun.pl/cgi-bin/BG/Z2Wumk/z2w_f.pl?kl=5217-1138283783&dis… (Nawet jeden u teologii :P). stara edycja 1995 - 5 kopii http://lx.bu.uni.torun.pl/cgi-bin/BG/Z2Wumk/z2w_f.pl?kl=5217-1138283783&dis… Być może kupimy też 2-3 dla CA-UMK - jeden ,,czytać na miejsce", dwie ,,zbior" ? Nie wiem jak jest doświadczenie ,,czyt" vs ,,zbior" w CA-UMK - chyba bibliotarka i studenci lepiej znają niż mnie... pozdr boud

1 0

Accuracy of Planck vs. WMAP re universe age (fwd)
by Andrzej Marecki 24 Jan '06

24 Jan '06

There is a discussion thread on Planck mission on sci.astro.research. The 1st posting in this thread is attached. -- a. Newsgroups: sci.astro.research Subject: Accuracy of Planck vs. WMAP re universe age Date: Mon, 23 Jan 06 11:49:03 GMT Organization: http://groups.google.com Lines: 8 Approved: sci.astro.research-request(a)slimy.greenend.org.uk (mjh) Message-ID: <mt2.0-22784-1138016943(a)hercules.herts.ac.uk> Hi - does anybody have a rough idea of the increase in accuracy which the upcoming ESA Planck CMB Probe will give us regarding the age of the universe? The combined results of WMAP, BABAR et al gave us an age of ~13.7 (+/- .2) *10^9 years. Ie: How much will Planck improve on this value and its error bars? thanks, Gene -- end of forwarded message --

1 0

[astro-ph/0510760] Constraints on changes in fundamental constants from a cosmologically distant OH absorber/emitter
by Andrzej Marecki 04 Jan '06

04 Jan '06

Better late than never... Only now I have spotted this: http://de.arxiv.org/abs/astro-ph/0510760 See also NRAO Press Release: http://www.nrao.edu/pr/2005/constants/ -- a.

2 1

H_0 stuff - christmas/new year meeting...
by Boud Roukema 22 Dec '05

22 Dec '05

hi everyone, Bartek L should be around for the next few days or so, also Krzyszek K - we'll try to meet up to talk about H_0/jet stuff. If anyone else is interested in meeting, try to find us by email, sms, gabber/gadu-gadu or whatever. So far we don't know when/where we'll meet up... Weso³y ¶wi±t itd itd :) pozdr boud

1 0

Nature's News Feature: Science in the Web age
by Andrzej Marecki 15 Dec '05

15 Dec '05

----- Forwarded message from NatureAlert <NatureAlert(a)info.nature.com> ----- [...] ---------------------- NEWS FEATURES ---------------------- Science in the web age: The expanding electronic universe Sarah Tomlin http://info.nature.com/cgi-bin24/DM/y/eV4x0BfWLH0Ch0qVj0ES Science in the web age: Joint efforts At its best, academia is a marketplace of ideas. But many scientists are reluctant to embrace the latest web tools that would allow them to communicate their ideas in new ways, says Declan Butler. http://info.nature.com/cgi-bin24/DM/y/eV4x0BfWLH0Ch0qVV0E7 Science in the web age: The real death of print Despite clashes with publishers over copyright, Google's plan to make millions of books available online is turning the tide for efforts to digitize the world's literature. Andreas von Bubnoff tracks the demise of the printed page. http://info.nature.com/cgi-bin24/DM/y/eV4x0BfWLH0Ch0qVk0ET Science in the web age: Start your engines Google has launched another challenge to commercial search services - this time aimed at scientists. But is the new engine running as smoothly as its fans hope? Jim Giles investigates. http://info.nature.com/cgi-bin24/DM/y/eV4x0BfWLH0Ch0qVW0E8 [...] ----- End forwarded message ----- P.S. The access to these articles is free. a.m.

2 4

couple of comments on the pixelization schemes
by Bartosz Lew 09 Nov '05

09 Nov '05

Hi Boud, I've been wondering about the optimal pixelization scheme of the sphere a couple of weeks ago and since I've send to you my own implementation of the Healpix pixelization scheme written (generally) in C (according to astro-ph/0409533) but compatible with GNU c++ compiler here I'd like to comment on some comments that can be found in the source code. And since you don't like private, closed conversations I also cc this letter to shape-univ. 1) First of all healpix is not stupid :)))) - it's cool because pixels have the same area which is not always the case (e.g.. quad-cube pixelization used with COBE data), because it's hierarchical and isolatitude of course, however the first and the last features are also common in other pixelization schemes. 1.1) But also very important thing is that it is more less "equi-angular" - i.e. the angular distance from pixel to pixel is more less constant. But obviously the exact "equi-angular" solution does not exist. 2) Now the my CPEDS library for doing useful stuff - and especially the pixelization.c has more useful functions so probably I should update the version I've send to you. i.e. - conversions from RING to NESTED and vice versa - calculation of ring given pixel and vice versa (in both nested and ring orderings) - estimated pixel size (maybe not that useful) since it may be probably just as well estimated from 4PI/N_pix. 3) The main point I wanted to come up with the new idea for pixelization scheme was the thing I addressed in point 1.1. But also the following 3 drawbacks of this scheme, namely: 3.1) the pixel shape dramatically varies from pixel to pixel. this is what I didn't like because of e.g. CMB lensing studies where the morphology at small scales would be very important - but of course this can be overcome with sufficiently oversampling the pixelization by increasing the Nside parameter to meet the Nyquist conditions. 3.2) the number of pixels in a ring does NOT gradually rises with increasing \theta (in spherical system definition consistent with HEALPIX - i.e. theta = 0 at North pole). Instead it only rises in the top (bottom) part of the north (south) polar region. This is certainly unnatural thing. since all the latitudes in equatorial (roughly from 41 deg to 180-41 deg regions are represented by the same amount of pixels in longitude) !! This is not the case e.g.. in he GLESP (Gauss-Legendre) or Igloo pixelization schemes. 3.3) It has an axial symmetry (since it has a poles equator, rings, etc). And why the CMB sky should know anything about the symmetry ? In particular why should it have an axial symmetry ? So naturally the solution would evolve into direction of platonic forms like tetrahedron, cube, ... oops it ends at icosahedron. And since we need a pixelization with number of pixels something like few Mpixels the 20 pixels of icosahedron is not enough. My idea of tetrahedron based pixelization system was just driven from this point of view that there should be no preferred directions in the sky. The system would gain higher resolution by looking for directions equally separated from neighboring directions (initially defined by axis of tetrahedron). This concept fails, of course because such a solution does not exist. Max Tegmark also went in this direction inventing the icosahedron pixelization system which is the next step after the quad-cube system, but each triangle is divided in other way. Anyway, at this time I see no point of terrible importance to force the idea of the tetrahedron pixelization system so I drop this case. rather it would be interesting to implement other pixelizations systems into the isolat packet. pozdr, Bartek

1 0

Why continue "Topologia Wszechswiata" research?
by Boud Roukema 21 Oct '05

21 Oct '05

Witam "Why continue funding for cosmic topology research?" ----------------------------------------------------------------------- The topology of the Universe (as an observational question) is one of the most fundamental questions of observational cosmology: it concerns the shape of the whole space-time that we live in. The Universe is clearly as important as any object inside the Universe. Knowing the "shape" of atoms, molecules, cells, mountains and continents is one of the basic steps in understanding any of these. At the moment, all that we are confident about regarding the shape of the Universe is a local property: it is "nearly" flat on the horizon scale; we do not know its global properties, such as its topology. Since the Toruń cosmology group is one of the most active groups in this field, funding this research topic is clearly a top priority. ----------------------------------------------------------------------- Staszek Krawczyk asked me to write why "Topologia Wszechswiata" is an important research topic which is "worth continuing", in 5 sentences, within the next 10 minutes or so (and the 10 minutes are already up). So that's what the above statement is about. (This is related to some funding request. i've wasted enough time in KBN requests with zero positive results, so if someone else is doing the admin/political work, i guess i won't complain...) Probably any feedback from cosmo-torun subscribers will be too late, but here it is anyway. pozdr boud

1 0

physics spam (but interesting anyway :P) Spacetime 100 Years Later (fwd)
by Boud Roukema 30 Sep '05

30 Sep '05

witam cosmo-torun, IOP to nie firma, która ewidentnie popiera otwarty dostęp do informacji, raczej ma tradycję zamkniętą. Jest dlaczego dla mnie, jest to raczej ,,spam". Jednakże, artykuły mogą być interesujący - dla osoby nie chętny do szukiwanie w arxiv.org. Np, raczej lubię artykuł Ashtekar'a: są dwa rodzaju ,,approaches" do grawitacji kwantowej - jeden w czymś jest m.in. teoria struń (jest teoria ,,perturbative", - drugi w czymś jest m.in. ,,loop quantum gravity" (związany z Ashtekarem) Ashtekar uważa, że z loop quantum gravity, nie ma osobliwość na a(t) = 0, bo zwykly czas-przestrzeń tam już nie ma. Więc, tu jest info ta. pozdr boud > ---------- Forwarded message ---------- > Date: Thu, 29 Sep 2005 15:18:21 +0100 (BST) > From: New Journal of Physics <njp at iop.org> > To: boud at astro.uni.torun.pl > Subject: Spacetime 100 Years Later > > Dear Dr Roukema > > You may be interested to know that New Journal of Physics > (http://www.njp.org) has just published the third of its three > celebratory Focus Issues to appear this year in connection with the > World Year of Physics. > All contributions to 'Spacetime 100 Years Later', edited by Richard > Price and Jorge Pullin, are permanently free to read at > http://www.njp.org/focus/spacetime. Each review article is also > listed below with a direct link. > Please don't hesitate to contact me with any comments or queries you > may have about this issue or NJP in general. > With best regards, > > Tim Smith > > Dr Tim Smith > Publisher, New Journal of Physics > E-mail: njp at iop.org > WWW: http://www.njp.org > Tel: +44 (0)117 930 1204 > Fax: +44 (0)117 920 0948 > > NJP 2004 Impact Factor = 3.095 > > > FOCUS ON SPACETIME 100 YEARS LATER > > Gravity and the quantum > A Ashtekar > http://stacks.iop.org/1367-2630/7/198 > > Black holes in astrophysics > R Narayan > http://stacks.iop.org/1367-2630/7/199 > > A most useful manifestation of relativity: gravitational lenses > E E Falco > http://stacks.iop.org/1367-2630/7/200 > > Spacetime in string theory > G T Horowitz > http://stacks.iop.org/1367-2630/7/201 > > Gravitational wave detectors > P Aufmuth and K Danzmann > http://stacks.iop.org/1367-2630/7/202 > > Hawking radiation and black hole thermodynamics > D N Page > http://stacks.iop.org/1367-2630/7/203 > > The basics of gravitational wave theory > E E Flanagan and S A Hughes > http://stacks.iop.org/1367-2630/7/204 > > Laboratory tests of gravity > J H Gundlach > http://stacks.iop.org/1367-2630/7/205 > _________________ > *Data Protection* > If you would prefer not to receive updates on our journals in future, please reply to this e-mail, entering the word 'Unsubscribe' in the body of your e-mail (please leave the subject line). > > IOP Publishing Limited is the data controller (data.protection at iop.org). > We will take all reasonable measures to prevent unauthorised or unlawful processing. >

1 0

Structured abstracts - A&A recommendation
by Andrzej Marecki 22 Sep '05

22 Sep '05

The Editors of A&A published the following recommendation to the authors. http://publish.edpsciences.org/articles/aa/pdf/2005/37/aa441100f.pdf -- a.

2 1

healpix goes GPL :)))))))
by Boud Roukema 05 Sep '05

05 Sep '05

witam healpix goes GPL :)))))))) http://cosmocoffee.info/viewtopic.php?p=972 pozdr boud

1 0

phd candidate(s) for cosmology starting 2005/2006 ?
by Boud Roukema 11 Jul '05

11 Jul '05

Witam, We have at least one candidate to do a PhD in cosmology at TCfA. :) Because the details include personal data, IMHO i should not send any personal stuff on public lists - but anyone who feels they have a right to participate (to some extent) in informal decision-making related to PhD candidates can contact me (or Andrzej Marecki/Kus) offlist for more details. (AFAIK the formal decision is made by a committee of Wydzia³ Fizyki AiIS). pozdr boud

1 0

CMB person - few days visit, nov/dev/jan - Jacques Delabrouille
by Boud Roukema 18 Mar '05

18 Mar '05

Witam, Jacques Delabrouille is likely to come to TCfA for a visit of a few days sometime during the next few months. He's a CMB cosmologist from Paris (College de France). You can see the CMB stuff he does here: http://de.arxiv.org/find/astro-ph/1/delabrouille/0/1/0/all/3/0 You can email him directly at delabrouille at cdf.in2p3.fr pozdr boud

2 1

http://cosmocoffee.info Witamy :)
by Boud Roukema 25 Feb '05

25 Feb '05

Witam, W kosmologii, ju� u�ywamy astro-ph od dawno, i prawie ka�dy artyku� powa�ny w kosmo jest na astro-ph. Jednak�e, gdzie rozmawia� z kolegami o najostatnich artyku�y? Na twiki na adjani, jest *technicznie* mo�liwe zrobi� fajne rozmowy, tylko w tej chwili jeszcze nie ma spo�ecze�stwo - jest mniej-wi�cej tylko boud ;). Wi�c... teraz jest: http://cosmocoffee.info Jest forum phpBB o artyku��w astro-ph - szczeg�lowie kosmo, oczywi�cie. Te� o software jak cmbfast itd itd itd. Formalnie, jest otwarty tylko dla autor�w astro-ph ,,i studenci" - tzn raczej doktoranci, ale je�li m�odsze studenci robi� konstruktywne komentarze tam, nie wierz� �e b�d� ich cenzurowane... By� autorem A&A/ApJ/MNRAS, chyba to nie wystarczy, musisz istnie� elektronicznie ;). boud

1 0

(fwd) Crisis in Cosmology
by Andrzej Marecki 15 Feb '05

15 Feb '05

-- forwarded message -- Path: news.man.torun.pl!newsfeed.pionier.net.pl!news-fra1.dfn.de!newsfeed.hanau.net!newsfeed01.sul.t-online.de!t-online.de!newsfeed.stueberl.de!ecngs!feeder.ecngs.de!195.40.0.165.MISMATCH!easynet-monga!easynet.net!feed4.jnfs.ja.net!feed2.jnfs.ja.net!jnfs.ja.net!gemini.csx.cam.ac.uk!news.cam.ac.uk!not-for-mail From: bda(a)fisica.uminho.pt Newsgroups: sci.astro.research Subject: Crisis in Cosmology Date: Mon, 14 Feb 05 17:55:41 GMT Organization: http://groups.google.com Lines: 6 Approved: sci.astro.research-request(a)slimy.greenend.org.uk (mjh) Message-ID: <mt2.0-21535-1108403741(a)hercules.herts.ac.uk> NNTP-Posting-Host: rapun.sel.cam.ac.uk X-Posting-Tool: modtool v2.0 Originator: mjh(a)hercules.herts.ac.uk ([147.197.230.144]) Xref: news.man.torun.pl sci.astro.research:5284 This is an announcement for the 1st Crisis in Cosmology Conference (CCC-I) which will be held in Portugal in the period 23-25 June 2005. All information can be obtained from http://www.cosmology.info Best regards, Jose B. Almeida -- end of forwarded message -- -- ----------------------------------------------------------------------------- Andrzej Marecki | Torun Centre for Astronomy | e-mail: amr(a)astro.uni.torun.pl N. Copernicus University | WWW: http://www.astro.uni.torun.pl ul. Gagarina 11 | tel: +48 56 6113032 PL-87-100 Torun, POLAND | fax: +48 56 6113009 ----------------------------------------------------------------------------- "If Bill Gates actually had to admin his own stuff, he'd shoot himself." -----------------------------------------------------------------------------

1 0

CARTIER PIAGET - Just Like the Real Thing - Logines Louis Vuitton Omega - 592049
by Kathryn Small 04 Feb '05

04 Feb '05

K798SI88 PIAGET CARTIER - Expensive Look Not Expensive Price - Louis Vuitton Omega Logines - 025154 You don't want to miss this - http://marquee.icfbingknd.com/?btdJJgIEfMOjGbbmillenarian no more - http://intrepid.akefbahj.com/chateaux?NzjjjmieRSopghhannulling g488D752

1 0

← Newer
1
2
3
4
5
6
7
8
9
...
14
Older →

Jump to page:

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

Cosmo-torun