From boud w astro.uni.torun.pl Wed Mar 4 17:14:14 2009 From: boud w astro.uni.torun.pl (Boud Roukema) Date: Wed, 4 Mar 2009 17:14:14 +0100 (CET) Subject: [Cosmo-torun] Fri 6 March - Zbyszek Bulinski - T^3 and Poincare dodecahedral space In-Reply-To: References: Message-ID: hi cosmo-torun, As we said last week: 16.00 Fri 6 March @KRA - Zbyszek will tell us about where he's got to in his T^3 and Poincare space modelling (i won't say details on this list, because the work is, for obvious reasons, so far unpublished :), and we can give some feedback. pozdr boud On Fri, 27 Feb 2009, Boud Roukema wrote: > witam cosmo-torun > > * circular polarisation from synchrotron processes? > > Kennett & Melrose, 1998, PASA, 15, 211 > http://www.atnf.csiro.au/pasa/15_2/kennett/paper/node3.html > >> In some sources it may be that the relativistic >> particles are electron-positron pairs (e.g., Wilson & >> Weiler 1997). Electrons and positrons contribute with >> the same sign to the linearly polarized component and >> with the opposite sign to the circularly polarized >> component. If the distributions of electrons and >> positrons are the same the wave modes can have no >> circular component and, more importantly, the intrinsic >> circular polarization from the synchrotron radiation >> sums to zero. > > So if we have different distributions of electrons and > positrons, then we get a circular polarisation component. > > i'm sure there must be more basic texts on this subject... > > pozdr > boud > > _______________________________________________ > Cosmo-torun mailing list > Cosmo-torun w cosmo.torun.pl > http://cosmo.torun.pl/mailman/listinfo/cosmo-torun > From boud w astro.uni.torun.pl Tue Mar 10 16:20:05 2009 From: boud w astro.uni.torun.pl (Boud Roukema) Date: Tue, 10 Mar 2009 16:20:05 +0100 (CET) Subject: [Cosmo-torun] Fri 13 March - Bartek Lew - primordial non-Gaussianities In-Reply-To: References: Message-ID: hi everyone, 16.00 Fri 13 March @KRA - Bartek will talk about primordial non-gaussianities, i assume from inflationary models, i.e. "primordial" means z >> 1000. pozdr boud From boud w astro.uni.torun.pl Thu Mar 12 13:22:44 2009 From: boud w astro.uni.torun.pl (Boud Roukema) Date: Thu, 12 Mar 2009 13:22:44 +0100 (CET) Subject: [Cosmo-torun] Fri 13 March - Bartek Lew - primordial non-Gaussianities In-Reply-To: References: Message-ID: hi cosmo-torun Change of topic. Bartek has changed his talk to an observational analysis talk, about large scale CMB multipoles alignment problems: 16.00 Fri 13 March @KRA pozdr boud On Tue, 10 Mar 2009, Boud Roukema wrote: > hi everyone, > > 16.00 Fri 13 March @KRA - Bartek will talk about primordial > non-gaussianities, i assume from inflationary models, i.e. > "primordial" means z >> 1000. > > pozdr > boud > > _______________________________________________ > Cosmo-torun mailing list > Cosmo-torun w cosmo.torun.pl > http://cosmo.torun.pl/mailman/listinfo/cosmo-torun > From boud w astro.uni.torun.pl Wed Mar 18 13:25:25 2009 From: boud w astro.uni.torun.pl (Boud Roukema) Date: Wed, 18 Mar 2009 13:25:25 +0100 (CET) Subject: [Cosmo-torun] Fri 20 March - Boud Roukema - topic TBD In-Reply-To: References: Message-ID: hi cosmo-torun, It's my turn to give a talk this Friday @16.00, but i'm still thinking over what i'll present... More soon... Meanwhile, here's a followup of the discussion we had a few weeks ago. See Eq.(32), page 11, of Andrew Liddle's 1999 introduction to inflation (quite nice): http://arXiv.org/pdf/astro-ph/9901124. This quite clearly points out that in comoving units, the horizon including an inflationary epoch is >> than the matter horizon. More formally: present particle horizon if there was an inflationary epoch = \int_{t_*}^{t_0}} dt/a(t) > \int_{t_*}^{t_{dec}} dt/a(t) \gg \int_{t_{dec}}^{t_0} dt/a(t) \sim present particle horizon assuming no inflationary epoch where * the > is because a(t) > 0 and t_0 > t_dec ; * the \gg is Eq. (32), i.e. it's "the basic strategy" that "solves the horizon problem" according to Andrew; * the \sim ignores everything between the end of inflation and decoupling, for simplicity of the discussion It looks to me like Andrew has been quite careful here - most of the time he uses the term "Hubble length", not "horizon". i suspect that in general, inflationary people make what is called an "abuse of language" - something that literally is wrong, but is said in practice because it's short and easy to say, and once you know the subject and think about it, it's clear what the correct meaning is even though what you say is literally incorrect. [For example, we often talk about an integral "to infinity", even though really we mean "a limit where N increases without bound", since there is no real number called infinity. It's easier to say "infinity".] It looks Andrew did fall back into this habit later on - see page 33 first paragraph. However, even on page 11 he was not as careful as he could have been, he wrote "the region of the Universe we can see", which could have been stated more carefully as "the region of the Universe we can see if we assume that there was no inflation". Back to the subject: compare Equations (25) and (32). Making the particle horizon *much* bigger is the whole point of inflation. pozdr boud From boud w astro.uni.torun.pl Thu Mar 19 15:38:39 2009 From: boud w astro.uni.torun.pl (Boud Roukema) Date: Thu, 19 Mar 2009 15:38:39 +0100 (CET) Subject: [Cosmo-torun] 16.00 Fri 20 March - Boud Roukema - the missing fluctuations problem + hot pixels In-Reply-To: References: Message-ID: Witam cosmo-torun On Wed, 18 Mar 2009, Boud Roukema wrote: > hi cosmo-torun, > > It's my turn to give a talk this Friday @16.00. i'll present and stimulate a discussion about: (1) the missing fluctuations problem - Copi et al. http://arXiv.org/abs/0808.3767 - new paper! + (2) the hot pixel correction for WMAP data - Aurich et al. http://arXiv.org/abs/0903.3133 - thanks to Bartek for pointing me to this :) pozdr boud From boud w astro.uni.torun.pl Sat Mar 21 01:43:53 2009 From: boud w astro.uni.torun.pl (Boud Roukema) Date: Sat, 21 Mar 2009 01:43:53 +0100 (CET) Subject: [Cosmo-torun] 16.00 Fri 20 March - Boud Roukema - the missing fluctuations problem + hot pixels In-Reply-To: References: Message-ID: hi cosmo-torun Next talk: Agnieszka will talk about something (maybe a journal article?) next week 16.00 Fri 27.03.2009. In this message, i'll try to clarify what got confused about Table 2 of Copi et al. 0808.3767. Partly this was my fault for not understanding what they did carefully enough. As it turns out, what they did is simpler than what i thought, but the results are consistent with what i summarised. In short, the statistical isotropy in independent spherical harmonics assumption is at least violated for 2 \le l \le 5 if we take the "best estimates" based on those assumptions; and if we use the best-fit infinite flat model instead of the "best estimates" directly, then we require l=2,3 to violate the same assumptions and extremely low C_2, C_3 values. Either from the observations "directly" or from the best-fit model, the statistical isotropy in independent spherical harmonics assumption is invalidated for either 4 or 2 l values respectively. Details of how Copi et al. get to these conclusions: On Thu, 19 Mar 2009, Boud Roukema wrote: > Witam cosmo-torun > > On Wed, 18 Mar 2009, Boud Roukema wrote: > >> hi cosmo-torun, >> >> It's my turn to give a talk this Friday @16.00. > > i'll present and stimulate a discussion about: > > (1) the missing fluctuations problem - Copi et al. > http://arXiv.org/abs/0808.3767 - new paper! http://arXiv.org/abs/0808.3767v1 - let's look at v1, in case later there is v2 and someone reads this email on the mailman archive. Table 2 page 8. The infinite, flat, gaussian-fluctuations-in-spherical-harmonics model says that the different l's are statistically independent. People often put error bars on the different C_l's and show a plot of the angular power spectrum with infinite-flat model vs observations + error bars, and then it looks like only the quadrupole is significantly in disagreement with the model. A key point of Copi et al. is that this interpretation is correct *only if* the statistical assumptions are correct. If the statistical assumptions are wrong, then the error bars cannot be interpreted as being independent from one another. Since the most common presentations of this data assume statistical independence and gaussianity in the spherical harmonics to extrapolate from high galactic latitudes to the "galactic plane" (e.g. KQ75 mask), these presentations are based on wrong assumptions. So what can be done to get a valid statistical statement? One answer is in Table 2 (bits in Table 1) and the accompanying discussion. Here's a simplified explanation. Let us *assume* that statistical isotropy and independence of C_l's are correct assumptions. (*) (1) Consider the line labelled "WMAP". Let us suppose that the "best" estimates of the C_l's are correct. Using assumptions (*), we have Eq.(3) and Eq.(6) of Copi et al., i.e. we can analytically calculate S using these C_l's. For example, this gives S = 8833 muK^4 in the 2nd last line of Table 1. Comparing this to 1152 muK^4 says that these C_l's have a lot of "power" in the galactic plane, which is the most suspicious part of the data set. But maybe just a few C_l's are "biased" by the galactic plane, and could be "removed" ? (2) Now, since we consider the galactic plane area to most likely to have systematic error, we decide to violate (*) for the lowest l's, and we find out how many C_l's can be chosen in a correlated ("tuned", "dependent") way in order for the full set of C_l's (tuned + untuned) to give an S that is consistent with the S for the high galactic latitudes (1152 muK^4). Naively, it might seem that we can set C_2 = 0, C_3 = 0, ..., C_i = 0 as "tuned" values, and then calculate S using the C_{i+1}, ..., C_8 untuned (same as the same "best" estimates), and we should get a lower S. However, Copi et al decide to allow even more "tuning", since it might happen that negative or positive "tuned" low C_l's are better than zero values for "cancelling" the high C_l's in order to get low S. [The P_l(cos theta)'s include negative values.] So they allow arbitrary violation of statistical isotropy/gaussianity in just a few C_l's, in order to try to "save" the statistical isotropy model. Then it is possible to argue that just a few C_l's are extreme events, and the other C_l's are OK. (3) Let's start with the first column, still in the row "WMAP" of Table 2. So the first number is 8290 muK^4. This means that allowing arbitrary values for C_2, either zero or negative or positive, it is *not* possible to get S anywhere near 1152 muK^4. (4) Next column, row "WMAP", we have 2530 muK^4. This means that for some "tuned" values (NOT given in the table) of C_2 and C_3, we can get S calculated from C_2, ..., C_8, ... C_infinity (value of "infinity" is probably not stated in the paper?) to be 2530 muK^4, but not any lower. This is still more than twice the high galactic latitude value of 1152. (5) Continue to columns C_4, C_5. It is only after we have "tuned" all of C_2, C_3, C_4, and C_5 *arbitrarily* in order to minimise S, that we can get the integral for C_2, ... C_infinity (which assumes (*) statistical isotropy) to give something as low as 1152 muK^4. In other words, we need a very special relationship between C_2, C_3, C_4 and C_5 in order for these plus the higher l observational C_l estimates to give a value of S \le 1152 \muK^4. Informally, we could say that this shows an "amplitude alignment" between all these four multipoles and the galactic plane, not just the quadrupole and the octopole with each other. This is not an alignment in orientation, it's a tuning of the amplitudes C_l, so "amplitude alignment" is probably a bad way to say this, but let's use this just for this discussion, where "amplitude alignment" is temporarily defined to mean the procedure done to get Table 2. Is it cosmologically reasonable to claim that the different C_l's are statistically independent from one another but that C_2, C_3, C_4, and C_5 are all "amplitude aligned" with each other and the Galactic Plane? (6) Now let's go to the line "Theory". This says that if we use the "best-fit" infinite flat model and then forget the fact that the actual measurements should be closer to the truth than the model, we do not have to do as much "tuning". It is enough to tune just C_2 and C_3, i.e. we get 922 muK^4 if we can choose some arbitrary values of C_2 and C_3 and then use C_4, ... C_infinity from the best-fit model (forgetting the measured values). So, we could say that we only need to "amplitude align" the quadrupole and octopole in order to get S \le 1152 muK^4, if we accept the best-fit infinite flat model and then forget about the measured values. However, i think what is meant in paragraph 3, page 7, 2nd column, is that the two C_l's which give this minimisation of S are 6 C_2/2\pi = 149 muK^2 and 12 C_3/2\pi = 473 muK^2. (i don't see any other reasonable interpretation of the sentence - i think it's just a typo between "Table 2" and "Table 1".) So, in order to "amplitude align" the quadrupole and octopole in order to get S \le 1152 muK^4 using the best-fit infinite flat model, the l(l+1)C_l/(2\pi) 's we get are 149 and 473 muK^2, as the true values. For l \ge 4 we have independence of C_l's and gaussian distributions, but for l=2,3, we have a special selection with these two values. These are very low values, see e.g. the last line of Table 1 - they should be about 1207 and 1114 muK^2 according to the infinite flat model with independent gaussian distributions in the spherical harmonics, not 149 and 473 muK^2. (Look at these on a typical C_l plot, e.g. Figs 3,4 Caillerie et al. arXiv:astro-ph/0705.0217.) So now let's get back to the question of statistical isotropy and statistically independent l's. Either for the observational estimates or the best-fit infinite flat model "estimates", we need to choose special values of the C_l's in order to get S \le 1152 muK^4. This means that representing the WMAP sky map in terms of statistically independent C_l's gives a representation of the data inconsistent with statistical isotropy - i.e. the galactic plane should not be special. One key point in Copi et al's conclusion is that they recommend that any attempted physical or statistical error or other explanation of the "low l" problems in the WMAP data should better concentrate on explaining the nearly zero two-point correlation function for theta > 60 degrees, rather than trying to explain the large length scale/angular scale problems in terms of low l spherical harmonics, since use of the low l spherical harmonics requires assumptions which are inconsistent with the properties of the observational data. A few things which may help if you are going to re-read this and the relevant bits of the paper in order to get things clear in your mind: * Table 2 does *not* show the tuned (correlated) C_l's which give the minimal S values. The table *only* shows the S values. One comment in the text (see above) gives what seem to be two C_l values in one case. Probably the table would have been clearer if C_l values had been listed too. In principle, it should not be difficult to calculate them. * The sum in Eq.(3) and the integral in Eq.(6) are taken over theta, *not* over 4 pi steradians. So it is invalid to say that the S values for the full sky and the cut sky calculated using Eqs (3) and (6) from the full sky and cut sky C_l values should be different unless statistical isotropy is violated. * If we consider the galactic plane region to have a serious systematic error (for the obvious reason), then we do not have a violation of statistical isotropy, and we don't have a quadrupole-octopole-ecliptic-plane alignment problem ("not readily testable"), but we do have C_theta which is unusually close to zero given the infinite flat statistically isotropic gaussian, k^1 spatial power spectrum model as a whole. In other words, rather than a violation of statistical isotropy, we have "The New Isotropy Problem" - the COBE and WMAP skies are *too* isotropic on scales greater than one present-day matter-horizon radius, i.e. 60 degrees in angular scale. pozdr boud > > + > (2) the hot pixel correction for WMAP data - Aurich et al. > http://arXiv.org/abs/0903.3133 - thanks to Bartek for > pointing me to this :) > > > pozdr > boud > > _______________________________________________ > Cosmo-torun mailing list > Cosmo-torun w cosmo.torun.pl > http://cosmo.torun.pl/mailman/listinfo/cosmo-torun > From szachula w astro.uni.torun.pl Tue Mar 24 15:54:34 2009 From: szachula w astro.uni.torun.pl (Agnieszka Szaniewska) Date: Tue, 24 Mar 2009 15:54:34 +0100 (CET) Subject: [Cosmo-torun] 16.00 Fri 27 March - Agnieszka Szaniewska - synchrotron radiation - dark matter annihilations In-Reply-To: References: Message-ID: Hi everyone, On Sat, 21 Mar 2009, Boud Roukema wrote: > hi cosmo-torun > > Next talk: Agnieszka will talk about something (maybe a journal > article?) next week 16.00 Fri 27.03.2009. I will talk about synchrotron radiation as a result of DM annihilations. You can read about it eg. here: http://xxx.lanl.gov/abs/hep-ph/0406083 Pozdr, Agnieszka > > > In this message, i'll try to clarify what got confused about Table 2 > of Copi et al. 0808.3767. Partly this was my fault for not > understanding what they did carefully enough. As it turns out, what > they did is simpler than what i thought, but the results are > consistent with what i summarised. > > In short, the statistical isotropy in independent spherical > harmonics assumption is at least violated for 2 \le l \le 5 > if we take the "best estimates" based on those assumptions; > and if we use the best-fit infinite flat model instead of > the "best estimates" directly, then we require l=2,3 to violate > the same assumptions and extremely low C_2, C_3 values. > > Either from the observations "directly" or from the best-fit > model, the statistical isotropy in independent spherical > harmonics assumption is invalidated for either 4 or 2 l values > respectively. > > Details of how Copi et al. get to these conclusions: > > > On Thu, 19 Mar 2009, Boud Roukema wrote: > >> Witam cosmo-torun >> >> On Wed, 18 Mar 2009, Boud Roukema wrote: >> >>> hi cosmo-torun, >>> >>> It's my turn to give a talk this Friday @16.00. >> >> i'll present and stimulate a discussion about: >> >> (1) the missing fluctuations problem - Copi et al. >> http://arXiv.org/abs/0808.3767 - new paper! > > http://arXiv.org/abs/0808.3767v1 - let's look at v1, in case later > there is v2 and someone reads this email on the mailman archive. > > Table 2 page 8. > > The infinite, flat, gaussian-fluctuations-in-spherical-harmonics model > says that the different l's are statistically independent. People often put > error bars on the different C_l's and show a plot of the angular > power spectrum with infinite-flat model vs observations + error bars, and > then it looks like only the quadrupole is significantly in disagreement > with the model. > > A key point of Copi et al. is that this interpretation is correct > *only if* the statistical assumptions are correct. If the statistical > assumptions are wrong, then the error bars cannot be interpreted as > being independent from one another. Since the most common > presentations of this data assume statistical independence and > gaussianity in the spherical harmonics to extrapolate from high > galactic latitudes to the "galactic plane" (e.g. KQ75 mask), these > presentations are based on wrong assumptions. So what can be done to > get a valid statistical statement? > > One answer is in Table 2 (bits in Table 1) and the accompanying > discussion. Here's a simplified explanation. > > Let us *assume* that statistical isotropy and independence of C_l's > are correct assumptions. (*) > > (1) Consider the line labelled "WMAP". Let us suppose that the "best" > estimates of the C_l's are correct. Using assumptions (*), we have > Eq.(3) and Eq.(6) of Copi et al., i.e. we can analytically calculate > S using these C_l's. For example, this gives S = 8833 muK^4 in the > 2nd last line of Table 1. Comparing this to 1152 muK^4 says that > these C_l's have a lot of "power" in the galactic plane, which is > the most suspicious part of the data set. But maybe just a few C_l's > are "biased" by the galactic plane, and could be "removed" ? > > > (2) Now, since we consider the galactic plane area to most likely to > have systematic error, we decide to violate (*) for the lowest l's, > and we find out how many C_l's can be chosen in a correlated ("tuned", > "dependent") way in order for the full set of C_l's (tuned + untuned) > to give an S that is consistent with the S for the high galactic > latitudes (1152 muK^4). > > Naively, it might seem that we can set C_2 = 0, C_3 = 0, ..., C_i = 0 > as "tuned" values, and then calculate S using the C_{i+1}, ..., C_8 > untuned (same as the same "best" estimates), and we should get a lower > S. However, Copi et al decide to allow even more "tuning", since it > might happen that negative or positive "tuned" low C_l's are better > than zero values for "cancelling" the high C_l's in order to get low > S. [The P_l(cos theta)'s include negative values.] So they allow arbitrary > violation of statistical isotropy/gaussianity in just a few C_l's, > in order to try to "save" the statistical isotropy model. Then it is > possible to argue that just a few C_l's are extreme events, and the other > C_l's are OK. > > (3) Let's start with the first column, still in the row "WMAP" of Table 2. > So the first number is 8290 muK^4. This means that allowing arbitrary > values for C_2, either zero or negative or positive, it is *not* possible > to get S anywhere near 1152 muK^4. > > (4) Next column, row "WMAP", we have 2530 muK^4. This means that for > some "tuned" values (NOT given in the table) of C_2 and C_3, we can > get S calculated from C_2, ..., C_8, ... C_infinity (value of > "infinity" is probably not stated in the paper?) to be 2530 muK^4, but > not any lower. This is still more than twice the high galactic > latitude value of 1152. > > (5) Continue to columns C_4, C_5. It is only after we have "tuned" all > of C_2, C_3, C_4, and C_5 *arbitrarily* in order to minimise S, that > we can get the integral for C_2, ... C_infinity (which assumes (*) > statistical isotropy) to give something as low as 1152 muK^4. In > other words, we need a very special relationship between C_2, C_3, C_4 > and C_5 in order for these plus the higher l observational C_l > estimates to give a value of S \le 1152 \muK^4. > > Informally, we could say that this shows an "amplitude alignment" > between all these four multipoles and the galactic plane, not just the > quadrupole and the octopole with each other. This is not an alignment > in orientation, it's a tuning of the amplitudes C_l, so "amplitude > alignment" is probably a bad way to say this, but let's use this just > for this discussion, where "amplitude alignment" is temporarily > defined to mean the procedure done to get Table 2. > > Is it cosmologically reasonable to claim that the different C_l's are > statistically independent from one another but that C_2, C_3, C_4, and > C_5 are all "amplitude aligned" with each other and the Galactic > Plane? > > > (6) Now let's go to the line "Theory". This says that if we use the > "best-fit" infinite flat model and then forget the fact that the > actual measurements should be closer to the truth than the model, > we do not have to do as much "tuning". It is enough to tune just > C_2 and C_3, i.e. we get 922 muK^4 if we can choose some arbitrary > values of C_2 and C_3 and then use C_4, ... C_infinity from the > best-fit model (forgetting the measured values). > > So, we could say that we only need to "amplitude align" the quadrupole > and octopole in order to get S \le 1152 muK^4, if we accept the > best-fit infinite flat model and then forget about the measured > values. However, i think what is meant in paragraph 3, page 7, > 2nd column, is that the two C_l's which give this minimisation of S are > 6 C_2/2\pi = 149 muK^2 and 12 C_3/2\pi = 473 muK^2. (i don't > see any other reasonable interpretation of the sentence - i think it's just a > typo between "Table 2" and "Table 1".) > > So, in order to "amplitude align" the quadrupole and octopole in order > to get S \le 1152 muK^4 using the best-fit infinite flat model, the > l(l+1)C_l/(2\pi) 's we get are 149 and 473 muK^2, as the true values. > For l \ge 4 we have independence of C_l's and gaussian distributions, > but for l=2,3, we have a special selection with these two values. > These are very low values, see e.g. the last line of Table 1 - they > should be about 1207 and 1114 muK^2 according to the infinite flat > model with independent gaussian distributions in the spherical > harmonics, not 149 and 473 muK^2. (Look at these on a typical C_l > plot, e.g. Figs 3,4 Caillerie et al. arXiv:astro-ph/0705.0217.) > > > So now let's get back to the question of statistical isotropy and > statistically independent l's. Either for the observational estimates > or the best-fit infinite flat model "estimates", we need to choose > special values of the C_l's in order to get S \le 1152 muK^4. > > This means that representing the WMAP sky map in terms of statistically > independent C_l's gives a representation of the data inconsistent with > statistical isotropy - i.e. the galactic plane should not be special. > > One key point in Copi et al's conclusion is that they recommend that > any attempted physical or statistical error or other explanation of > the "low l" problems in the WMAP data should better concentrate on > explaining the nearly zero two-point correlation function for theta > > 60 degrees, rather than trying to explain the large length > scale/angular scale problems in terms of low l spherical harmonics, > since use of the low l spherical harmonics requires assumptions which > are inconsistent with the properties of the observational data. > > > A few things which may help if you are going to re-read this and > the relevant bits of the paper in order to get things clear in > your mind: > > * Table 2 does *not* show the tuned (correlated) C_l's which give > the minimal S values. The table *only* shows the S values. One comment > in the text (see above) gives what seem to be two C_l values in one > case. Probably the table would have been clearer if C_l values had > been listed too. In principle, it should not be difficult to calculate > them. > > * The sum in Eq.(3) and the integral in Eq.(6) are taken over theta, > *not* over 4 pi steradians. So it is invalid to say that the S values > for the full sky and the cut sky calculated using Eqs (3) and (6) > from the full sky and cut sky C_l values should be different unless > statistical isotropy is violated. > > * If we consider the galactic plane region to have a serious > systematic error (for the obvious reason), then we do not have a > violation of statistical isotropy, and we don't have a > quadrupole-octopole-ecliptic-plane alignment problem ("not readily > testable"), but we do have C_theta which is unusually close to zero > given the infinite flat statistically isotropic gaussian, > k^1 spatial power spectrum model as a whole. In other words, > rather than a violation of statistical isotropy, we have > "The New Isotropy Problem" - the COBE and WMAP skies are *too* > isotropic on scales greater than one present-day matter-horizon > radius, i.e. 60 degrees in angular scale. > > pozdr > boud > > > >> >> + >> (2) the hot pixel correction for WMAP data - Aurich et al. >> http://arXiv.org/abs/0903.3133 - thanks to Bartek for >> pointing me to this :) >> >> >> pozdr >> boud >> >> _______________________________________________ >> Cosmo-torun mailing list >> Cosmo-torun w cosmo.torun.pl >> http://cosmo.torun.pl/mailman/listinfo/cosmo-torun >> > > _______________________________________________ > Cosmo-torun mailing list > Cosmo-torun w cosmo.torun.pl > http://cosmo.torun.pl/mailman/listinfo/cosmo-torun > From boud w astro.uni.torun.pl Fri Mar 27 12:31:44 2009 From: boud w astro.uni.torun.pl (Boud Roukema) Date: Fri, 27 Mar 2009 12:31:44 +0100 (CET) Subject: [Cosmo-torun] =?iso-8859-1?q?Diffusion_PNCG=2C_mess=2E_n=B0_6_=28?= =?iso-8859-1?q?fwd=29?= Message-ID: hi all some interesting announcements pozdr boud > > ---------- Forwarded message ---------- > Date: Thu, 26 Mar 2009 16:46:49 +0100 > From: Programme National de Cosmologie et Galaxies > To: Programme National de Cosmologie et Galaxies > Subject: Diffusion PNCG, mess. n° 6 > > PNCG - Message n° 6 - 26 mars 2009 > > 1. Oxford Physics Department 2 Jobs Advert > > 2. NAM/JENAM 2009 : Epoch of Reionisation Session > > 3. Blois 2009 > > 4. Santa Fe Cosmology Summer Workshop for 2009 > > 5. Summer School in Statistics for Astronomers, June 1-6, 2009 > > ----------------------------------------------------------------------- > 1. Oxford Physics Department 2 Jobs Advert > > Please visit http://www.physics.ox.ac.uk/jobs/ to view this. > > *1* Vacancy Title: Post-doctoral Researchers in OBSERVATIONAL COSMOLOGY > within Astrophysics > > Reference Number: DB09005 > > Job Description: The Department of Physics invites applications for one > or more post-doctoral positions in observational cosmology. > > The observational cosmology programme at Oxford includes: the analysis > of surveys for type Ia supernovae; analysis of large-area surveys of > weak gravitational lensing incorporating photometric redshift estimation; > and the design and implementation of upcoming redshift surveys to measure > baryonic oscillations. We especially welcome applications from candidates > interested in working on any of these projects. > > The post-holder will have the opportunity to engage in teaching for up > to 3 hours per week during term. The starting salary is from £28,839 > to £38,757 pa depending on skills and experience. A benefits package > and a research budget for travel and other expenses will be provided. > Appointments will be for two years in the first instance, extendable > to three years. Appointments would start on 1 May 2009 or later. > > Further particulars are available from > http://www.physics.ox.ac.uk/astro/jobs/ > Applicants should send a statement of research interests, > curriculum vitae, list of publications (one file only in pdf), > and the names and addresses of three referees by the closing date > of 31 March 2009, quoting reference DB09005. Email submission is > preferred. Please ensure that the reference number DB09005 is > included in the subject title. In addition candidates should arrange > for letters from the referees to be sent to sec astro.ox.ac.uk by the > closing date. Interviews are expected to be held shortly after. > > > The University is an equal opportunity employer > > > Anyone who thinks they may be interested in the job is encouraged > to talk to Vanessa Ferraro-Wood (or email: sec astro.ox.ac.yuk) about it. > > The application deadline is 31/03/2009 > > > *2* Vacancy Title: Postdoctoral Researcher in Theoretical Cosmology > (Fixed Term) within Astrophysics > > Reference Number: DB09006 > > Job Description: We invite applications for a postdoctoral research > position starting 1 October, 2009 to work in the area of Theoretical > Cosmology for one year in the first instance, with the possibility of > extending to 3 years. There will be a particular focus on cosmic > microwave background anisotropy and interpretation of data from the > Atacama Cosmology Telescope and the Planck satellite. The successful > candidate is likely to have experience in analysis of cosmological data > and be capable of initiating research in a lively group with significant > interaction between theory and observation. The candidate will work > primarily with Joanna Dunkley, but will be encouraged to interact with > other faculty members and to carry out independent research. > > Oxford Astrophysics offers a stimulating research environment, with a > large number of faculty in cosmology, including theoretical (Pedro > Ferreira, Joe Silk, Adrianne Slyz), observational (Richard Ellis, Steve > Rawlings, Isobel Hook, Lance Miller) and experimental (Mike Jones, > Ghassan Yassin, Gavin Dalton). > > > Anyone who thinks they may be interested in the job is encouraged to > talk to Dr Joanna Dunkley (or email: j.dunkley1 physics.ox.ac.uk) about > it. > > > The application deadline is 31/03/2009 > > > ----------------------------------------------------------------------- > 2. NAM/JENAM 2009 : Epoch of Reionisation Session > > As part of the 2009 UK National Astronomy Meeting & the Joint European > National Astronomy Meeting at the University of Hertfordshire > (www.jenam2009.eu), there will be a parallel session on > > "Epoch of reionisation: > first light to the earliest galaxies currently known" > > on Monday 20th April 2009. > Please see www.jenam2009.eu/default.asp?ContentID=1327 > for more information. > > We would welcome submission of abstracts for this session by the > deadline on Monday March 9th. > > Registration and abstract submission is available at > www.jenam2009.eu/cmsapps/jenam_conference_reg/ > confreg2.asp?userid=0&confid=4&contentid=1329 > > ----------------------------------------------------------------------- > 3. Blois 2009 > > The XXIth Rencontres de Blois entitled "Windows on the Universe" > will be held from June 21st to June 26th, 2009 > in the Château de Blois, Loire Valley, France. > > This series, started in 1989 with the celebration of the > 25th anniversary of the discovery of CP violation, is a > high level cross disciplinary conference series which is > organized every year in May or June in the beautiful > Renaissance castle of Blois. > > This year will be the 20th anniversary of this series of > conferences; moreover, 2009 has also been tagged as the > "World year of astronomy". > To celebrate these two events, 7 Nobel laureates : J.Cronin, > R. Giacconi, D. Gross, M. Perl, G. Smoot, J. Steinberger, > J. Taylor and many other well known scientists have accepted > our invitation to attend and give a lecture. > > Registration and abstract submission for parallel session talks > are open at http://blois.in2p3.fr > > ----------------------------------------------------------------------- > 4. Santa Fe Cosmology Summer Workshop for 2009 > > The next of our continuing series of Santa Fe Cosmology Summer workshops > will be held in Santa Fe, New Mexico from July 6 to July 24, 2009. > The workshop series is sponsored by Los Alamos National Laboratory and > by the Kavli Institute for Cosmological Physics at the University of > Chicago. The venue is the campus of St. John's College, a small liberal > arts college that provides both a pleasant ambiance and convenient access > to Santa Fe. > > The aim of the Santa Fe workshops is to bring together physicists and > astrophysicists with interests in structure formation, the cosmic > microwave background, and the early universe. Typically, a large > portion of the time is devoted to discussion, with formal or informal > talks as needed to introduce such discussion. Attendance is limited > to about 80 participants to encourage this informality. We also > encourage attendance by a number of graduate students and junior > researchers, so they can be exposed to forefront research and interact > with leaders in the field. We therefore ask you to bring this meeting > to the attention of exceptional students and postdocs. > > This year, the first two weeks will follow our standard workshop > format, while the third week will be a focused workshop on weak > lensing. Details on third week activities will be available shortly. > > There will be no registration fee and highly subsidized housing will > be provided (the precise cost estimates will be available soon, but > are typically $150/week, less for students). Travel support will not > be available. > > To register for the meeting and to make suggestions for the scientific > program, go to the Workshop website at > > http://www.lanl.gov/projects/cosmology/sf09/ > > We will be filling spaces on a rolling basis, so you are strongly > advised to register as soon as possible, and preference will be given > to those who register before April 08, 2009. > > ----------------------------------------------------------------------- > 5. Summer School in Statistics for Astronomers, June 1-6, 2009 > > First Announcement > > Summer School in Statistics for Astronomers V > June 1-6, 2009 > Penn State University > http://astrostatistics.psu.edu/su09/ > > The fifth annual Penn State Summer School in Statistics for > Astronomers will be held at Penn State. This is a 6-day course > in fundamental statistical inference designed to provide > physical scientists, particularly young researchers in astronomy, > with a strong conceptual foundation in modern statistics and to > develop a repertoire of well-established techniques applicable > to observational astronomy. Classroom instruction is interspersed > with hands-on analysis of astronomical data using the public-domain > R software package. The course is taught by a team of statistics > and astronomy professors with opportunity for discussion of > methodological issues. > > Statistical techniques covered include: > > * exploratory data analysis > * hypothesis testing and parameter estimation > * regression & confidence interval estimation > * model selection & goodness-of-fit > * maximum likelihood methods & Bayes' Theorem > * non-parametric methods > * Monte Carlo methods > * Poisson processes > * time series analysis > > INTERESTED PARTICIPANTS SHOULD REGISTER AT > http://astrostatistics.psu.edu/su09/reg.html > REGISTRATION DEADLINE: May 1, 2009 > (or when the enrollment limit reaches) > REGISTRATION FEE: $250. > > The 2009 Summer School is organized by Penn State University's > Center for Astrostatistics. It will be modeled on the last four Penn > State Summer Schools and the 2008 Indian Institute of Astrophysics- > Penn State Summer School. See http://astrostatistics.psu.edu/ > for past lecture notes. This Web site > http://astrostatistics.psu.edu/su09/ > also gives information on travel, lodging, and visas. > From szachula w astro.uni.torun.pl Mon Mar 30 12:36:36 2009 From: szachula w astro.uni.torun.pl (Agnieszka Szaniewska) Date: Mon, 30 Mar 2009 12:36:36 +0200 (CEST) Subject: [Cosmo-torun] 16.00 Fri 03 April In-Reply-To: References: Message-ID: hi cosmo-torun Next talk - I asked Bartek to take my place and take care of Friday's meeting, because I will probably absent this week. Pozdr, Agnieszka