Measurements of BAO feature: separately in projection [dA(z)] and parallel [H(z)] to the line of sight. Internal consistency check.
dV = dA^2 H^{-1} ?!
kperp = alphainv (1+epsilon) kperp
kpar = alphainv (1+epsilon)^{-2} kpar
alpha shifts the correlation function. epsilon creates a shear pattern.
P(k,mu)= \Sum P_l(k) Legendre(mu)
Instead of multipole expansions do expansion in wedge basis functions: Kazin et al. 2011.
xi(r) = xitemplate(r/alpha) + fsmooth(r)
fsmooth contains nuisance parameters: and the idea will be to find the angular diameter distance with high fidelity.
Non-linear evolution washes out oscillations: can be seen from comparison with simulations.
Eulerian perturbation theory:
P(k)=d1d1+d1d3+d2d2
<d1dn>
Lagrangian perturbation theory:
x=q+\Psi(q)
BAO ring smeared out by coherent bulk flows. You can use Zeldovich approximation and calculate the smearing out (Eisenstien, Seo White 07), or by renormalized Eulerian perturbation theory (Scoccimarro 08) or Lagrangian perturbation theory (Matsubara 09?)...
Ptemp = Plin exp (-k^2 \Sigma^2/2)
This still gives some shifts and those come because of the P22 term
Ptemp = (Plin + P22)exp (-k^2 \Sigma^2/2)
Galaxy bias needs to be included, but it turns out this looks more like P22.
Reconstruction: Smooth the density field on some large scale, calculate the linear overdensity, get the Zeldovich approximation and move back the galaxies by this displacement and then measure the correlation function... It also isotropizes the correlation function in 3d space. It somehow does better than the Plin + P22 case. I am not sure I understand why.. It seems its getting more information out than just the Plin+P22 approach.
Beth Reid
Redshift space distortions: Model for halo redshift space distortions.
RSD can help you distinguish between Modified gravity and dark energy.
Introduction to RSDs.
Kaiser formula approximation: dv_z/dz is small, \Delta. v = f \delta_m, and linearly biased tracers.
Streaming model:
Fisher 1995.
Pg(k,mu)=(b+fmu^2) Pm(k) exp(-k^2\sigma^2mu^2)
1+\xi(s) = \int dy (1+\xi(y)) P( vz=rpi-y)
Kaiser limit may not work correctly! So this needs to be properly accounted for. Check Reid et al. submitted to arxiv in May...
Velocity field suppressed compared to linear theory.. Addition of power due to mapping between redshift space and real space correlation function.
Machine gun talks
Aurel Schneider: WDM cosmology artificial haloes in filaments.
Stark: Numerical simulations visualization.
Doug Watson: Do satellite galaxies trace dark matter distribution?
Hyunmi Song: first filaments in MDM model. massive neutrinoes. Merging on haloes on filaments which then collapse along their axis, high z quasar formation.
Jennifer Helsby: Improving photometric redshifts at the faint end.
Jessi Muir (MSU): Galaxy cluster surveys constraints on cosmological parameters.
John Parejko: BOSS galaxies measurements of correlation functions
Rahul Biswas: SNeIa cosmology with DES, designing follow up strategy.
Yookyung Noh: Galaxy clusters and their filamentary event.
Bulk flow motion
Variation of magnitudes across the sky.
Nights get clearer over time. And SDSS scanning strategy can create problems.
Mock catalogs and bulk flow. Nusser and Davis
GAMA: redshift survey design.
Using different telescopes for redshift followup and imaging.
July 12 2011
Tijana Prodanovic
Measuring abundances
Deuterium: Absorption towards QSO
3He: galactic HII regions
4He: extragalactic HII regions
7Li: low metallicity stars
3He is hopeless. Stars burn D to 3He so there are sinks and sources. So model dependent to go from 3He form galaxy to primordial.
4He: extragalactic HII regions. Measure as a function of O/H and extrapolate to zero O/H.
7Li: fragile but destroyed in stars. cosmic rays can create 7Li, and neutrino process in SN. but the main contribution is still 7Li. Use stars who do not have convection.
Deuterium: Only gets destroyed through stellar processing. High z quasar absoroption systems. Only handful of systems.
Abundance of 7Li is not consistent with the measurements of CMB. May be due to primordial CRs. It can produce 7Li.
Find 7Li line in absorption in stellar atmospheres, complex radiative transfer modelling may be required. May be the convective zones in stars, but difficult to destroy at all metallicities and in all stars uniformly.
Deuterium is not a problem when compared to the CMB results, but locally there is a large scatter...
Prodanovic et al. (2010) : Using all lines of sight for De abundance.
General models of early universe with scale invariant perturbations.
Moradinezhad
Generating 3 decades in wavelength of scale invariant perturbations require one of the 3 things:
Inflation
Superplanckian energy density
superluminal speed of sound
Sam Schmidt Photometric redshifts:
All next gen surveys are photometric.
Use a spectral template and use it to get redshift. Baum 1962.
Photoz's use broadband photometry information.
Lyman break or the 4000 Angstrom break.
Proper photometry critical: accuracy should be 0.01-0.03 mag (S/N ~30)
Quantum efficiency goes down with temperature???
Coe 2006 to measure colours from images with different seeing.
Polynomials used to get photozs from bunch of observables. Check Cunha 2008 for more references.
No errorbars on templates.
Templates: CWW and SB template mismatch variance.
Catastrophic outliers.
Benitez 2000 Bayesian framework using priors on the presence of a certain magnitude galaxy at redshfit z.
p(z) estimates should be used almost always. PHAT paper for comparison with different photo-z codes.
Kernel regression techniques: Udaltsova and Schmidt (to appear soon)
Color tomography: Jain 2007 Cut bad parts of the color space.
Using more than colour: surface brightness, size area
Paper by Jain's student using surface brightness
Abrahamse 2010
Quadri et al. (2009): Using the clustering information to learn about catastrophic outliers.
Benjamin et al. (2010):
Jasche and Wandelt (2011): Using isotropy and the clustering information.
Newman 2008 and MAtthews 2010: Cross correlate spec sample with photoz sample. Spec sample need not be representative but should span the entire redshift range.
Joanne Cohn:
Theory masses, correlated scatter
Paul Ricker, Sutter, Karen Yang:
Getting the M-sigma relation correct: requires following halo mergers at every time step, and whether you set the seed black holes on the M-sigma relation or not or a constant seed mass.
Karen's thesis: Isolated cluster and numerical tests to understand the AGN feedback processes, bubble sizes, jets...
Chris Carilli:
Reionization: When, how fast and what sources?
Constraint 1: CMB large scale polarization due to Thomson scattering. Opacity ~ d n_e \sigma_T
Constraint 2: Gunn Peterson effect. (Resonant scattering?! Absorption): SDSS quasars beyond z~6. This means f_{HI} ~ 1E-3 .
UV luminosity vs redshift: No correlation
Near zone size vs L_{uv}: Some correlation consistent with Stromgen sphere calculation.
Near zone size vs redshift: Smaller sizes at high redshift.
Proximity zone: Photons from quasars and photons from reionization.
z~7.1 quasar. Damped Ly alpha profile shortward of Ly alpha.
LBG at z~7: fraction of LBGs in which you detect Ly alpha is less at z~7 than at 6. Perhaps due to interloper LBGs. Attenuation of Ly alpha emmision. Pentericci et al. 2011.
Reinoization changes by a factor of 1000 from z~6 to 7.
CO Intensity mapping: Cross correlate the HI signal with galaxy surveys. Galaxy surveys are difficult to get so do it via CO intensity.
Quasars cant do it, so first stars should be included. May be some contributions from He reionization.
First stars: smaller size, extremely hot temperature due to composition. These are more efficient at destroying neutral hydrogen.
Only the pp chain is available for nuclear reactions until trace amounts of metals form. The pp chain has low temperature dependence. And so the star has to collapse further before it can support itself, which makes the size smaller.
Xrays can cause some seeding of IGM reionization. Xrays ionize HeI -> photo electrons -> secondary ionization of HI.
HeI sees the Xrays first, the mean free path is lower than for HeII and HI.
Habib:
Exascale crisis
Stadel
Elser 2011
Grimm and Stadel 2011
Read about OpenCL, GPGPU, CUDA
Adam Lidz:
Furlanetto et al. (2004) seminumerical model for reionization. Zahn et al. 2006.
Things to understand from percolation theory: Reionization, Spread of metals and so on
Neal Dalal:
Spherical collapse
Ellipsoidal collapse (Bond and Myers 1996) collapse of uniform isolated sphere including a background tide. Unclear what to do after first axis collapses. The collapse occurs later than spherical collapse.
Collapse of a scale free non-spherical profile.
\delta rho \propto r^{-gamma} f(theta,phi)
The solution is self similar. Things at different r will go through similar phases at different times.
BBKS (1986):
Npeak(nu), triaxiality, initial radial density profile.
n(>M) = int de \int_{pc}^{\infty} dp dnu N(e,p,nu,M)
FOF dn/dM for \Omega_m=1, P(k) \propto const., this model works perfectly but the fitting functions break down.
Adiabatic invariants if the potential changes slowly compared to orbital time.
The radial action J_r = \int v_r dr
M_L r_{ta} is the adiabatic invariant.
Matteo Viel
Neutrino effects on the power spectrum of total matter: Check the latest arxiv paper.
High redshift voids also get affected. Navarro-Villaescusa 2011
Highlights section:
Nikhil Padmanabhan: reconstructing the BAFs in redshift space and projected space separately.
Tijana: Primordial abundances are not all hunky dory yet.
Jasche and Wandelt 2011: Interesting idea to reduce the error on photoz-s by an order of magnitude.
Adam Lidz and co: CO intensity mapping and cross correlating with the 21 cm signal to confirm high-z nature of both signals.
Martin White: Modelling of the 3d lyman alpha forest.
De/Re-constructing BAOs.
Linear theory description of BAOs.
Measurements of BAO feature: separately in projection [dA(z)] and parallel [H(z)] to the line of sight. Internal consistency check.
dV = dA^2 H^{-1} ?!
kperp = alphainv (1+epsilon) kperp
kpar = alphainv (1+epsilon)^{-2} kpar
alpha shifts the correlation function. epsilon creates a shear pattern.
P(k,mu)= \Sum P_l(k) Legendre(mu)
Instead of multipole expansions do expansion in wedge basis functions: Kazin et al. 2011.
xi(r) = xitemplate(r/alpha) + fsmooth(r)
fsmooth contains nuisance parameters: and the idea will be to find the angular diameter distance with high fidelity.
Non-linear evolution washes out oscillations: can be seen from comparison with simulations.
Eulerian perturbation theory:
P(k)=d1d1+d1d3+d2d2
<d1dn>
Lagrangian perturbation theory:
x=q+\Psi(q)
BAO ring smeared out by coherent bulk flows. You can use Zeldovich approximation and calculate the smearing out (Eisenstien, Seo White 07), or by renormalized Eulerian perturbation theory (Scoccimarro 08) or Lagrangian perturbation theory (Matsubara 09?)...
Ptemp = Plin exp (-k^2 \Sigma^2/2)
This still gives some shifts and those come because of the P22 term
Ptemp = (Plin + P22)exp (-k^2 \Sigma^2/2)
Galaxy bias needs to be included, but it turns out this looks more like P22.
Reconstruction: Smooth the density field on some large scale, calculate the linear overdensity, get the Zeldovich approximation and move back the galaxies by this displacement and then measure the correlation function... It also isotropizes the correlation function in 3d space. It somehow does better than the Plin + P22 case. I am not sure I understand why.. It seems its getting more information out than just the Plin+P22 approach.
Beth Reid
Redshift space distortions: Model for halo redshift space distortions.
RSD can help you distinguish between Modified gravity and dark energy.
Introduction to RSDs.
Kaiser formula approximation: dv_z/dz is small, \Delta. v = f \delta_m, and linearly biased tracers.
Streaming model:
Fisher 1995.
Pg(k,mu)=(b+fmu^2) Pm(k) exp(-k^2\sigma^2mu^2)
1+\xi(s) = \int dy (1+\xi(y)) P( vz=rpi-y)
Kaiser limit may not work correctly! So this needs to be properly accounted for. Check Reid et al. submitted to arxiv in May...
Velocity field suppressed compared to linear theory.. Addition of power due to mapping between redshift space and real space correlation function.
Machine gun talks
Aurel Schneider: WDM cosmology artificial haloes in filaments.
Stark: Numerical simulations visualization.
Doug Watson: Do satellite galaxies trace dark matter distribution?
Hyunmi Song: first filaments in MDM model. massive neutrinoes. Merging on haloes on filaments which then collapse along their axis, high z quasar formation.
Jennifer Helsby: Improving photometric redshifts at the faint end.
Jessi Muir (MSU): Galaxy cluster surveys constraints on cosmological parameters.
John Parejko: BOSS galaxies measurements of correlation functions
Rahul Biswas: SNeIa cosmology with DES, designing follow up strategy.
Yookyung Noh: Galaxy clusters and their filamentary event.
Bulk flow motion
Variation of magnitudes across the sky.
Nights get clearer over time. And SDSS scanning strategy can create problems.
Mock catalogs and bulk flow. Nusser and Davis
GAMA: redshift survey design.
Using different telescopes for redshift followup and imaging.
July 12 2011
Tijana Prodanovic
Measuring abundances
Deuterium: Absorption towards QSO
3He: galactic HII regions
4He: extragalactic HII regions
7Li: low metallicity stars
3He is hopeless. Stars burn D to 3He so there are sinks and sources. So model dependent to go from 3He form galaxy to primordial.
4He: extragalactic HII regions. Measure as a function of O/H and extrapolate to zero O/H.
7Li: fragile but destroyed in stars. cosmic rays can create 7Li, and neutrino process in SN. but the main contribution is still 7Li. Use stars who do not have convection.
Deuterium: Only gets destroyed through stellar processing. High z quasar absoroption systems. Only handful of systems.
Abundance of 7Li is not consistent with the measurements of CMB. May be due to primordial CRs. It can produce 7Li.
Find 7Li line in absorption in stellar atmospheres, complex radiative transfer modelling may be required. May be the convective zones in stars, but difficult to destroy at all metallicities and in all stars uniformly.
Deuterium is not a problem when compared to the CMB results, but locally there is a large scatter...
Prodanovic et al. (2010) : Using all lines of sight for De abundance.
General models of early universe with scale invariant perturbations.
Moradinezhad
Generating 3 decades in wavelength of scale invariant perturbations require one of the 3 things:
Inflation
Superplanckian energy density
superluminal speed of sound
Sam Schmidt Photometric redshifts:
All next gen surveys are photometric.
Use a spectral template and use it to get redshift. Baum 1962.
Photoz's use broadband photometry information.
Lyman break or the 4000 Angstrom break.
Proper photometry critical: accuracy should be 0.01-0.03 mag (S/N ~30)
Quantum efficiency goes down with temperature???
Coe 2006 to measure colours from images with different seeing.
Polynomials used to get photozs from bunch of observables. Check Cunha 2008 for more references.
No errorbars on templates.
Templates: CWW and SB template mismatch variance.
Catastrophic outliers.
Benitez 2000 Bayesian framework using priors on the presence of a certain magnitude galaxy at redshfit z.
p(z) estimates should be used almost always. PHAT paper for comparison with different photo-z codes.
Kernel regression techniques: Udaltsova and Schmidt (to appear soon)
Color tomography: Jain 2007 Cut bad parts of the color space.
Using more than colour: surface brightness, size area
Paper by Jain's student using surface brightness
Abrahamse 2010
Quadri et al. (2009): Using the clustering information to learn about catastrophic outliers.
Benjamin et al. (2010):
Jasche and Wandelt (2011): Using isotropy and the clustering information.
Newman 2008 and MAtthews 2010: Cross correlate spec sample with photoz sample. Spec sample need not be representative but should span the entire redshift range.
Joanne Cohn:
Theory masses, correlated scatter
Paul Ricker, Sutter, Karen Yang:
Getting the M-sigma relation correct: requires following halo mergers at every time step, and whether you set the seed black holes on the M-sigma relation or not or a constant seed mass.
Karen's thesis: Isolated cluster and numerical tests to understand the AGN feedback processes, bubble sizes, jets...
Chris Carilli:
Reionization: When, how fast and what sources?
Constraint 1: CMB large scale polarization due to Thomson scattering. Opacity ~ d n_e \sigma_T
Constraint 2: Gunn Peterson effect. (Resonant scattering?! Absorption): SDSS quasars beyond z~6. This means f_{HI} ~ 1E-3 .
UV luminosity vs redshift: No correlation
Near zone size vs L_{uv}: Some correlation consistent with Stromgen sphere calculation.
Near zone size vs redshift: Smaller sizes at high redshift.
Proximity zone: Photons from quasars and photons from reionization.
z~7.1 quasar. Damped Ly alpha profile shortward of Ly alpha.
LBG at z~7: fraction of LBGs in which you detect Ly alpha is less at z~7 than at 6. Perhaps due to interloper LBGs. Attenuation of Ly alpha emmision. Pentericci et al. 2011.
Reinoization changes by a factor of 1000 from z~6 to 7.
CO Intensity mapping: Cross correlate the HI signal with galaxy surveys. Galaxy surveys are difficult to get so do it via CO intensity.
Martin White: Ly alpha overview
Doppler parameter: size of the line.
Fluctuating Gunn Peterson Approximation
Meiksin Rev Mod Phys 81, 1943
Aparna Venkatesan:
CMB reionization 10.6 \pm 1.12
Gunn Peterson effect: 6.5
Quasars cant do it, so first stars should be included. May be some contributions from He reionization.
First stars: smaller size, extremely hot temperature due to composition. These are more efficient at destroying neutral hydrogen.
Only the pp chain is available for nuclear reactions until trace amounts of metals form. The pp chain has low temperature dependence. And so the star has to collapse further before it can support itself, which makes the size smaller.
Xrays can cause some seeding of IGM reionization. Xrays ionize HeI -> photo electrons -> secondary ionization of HI.
HeI sees the Xrays first, the mean free path is lower than for HeII and HI.
Habib:
Exascale crisis
Stadel
Elser 2011
Grimm and Stadel 2011
Read about OpenCL, GPGPU, CUDA
Adam Lidz:
Furlanetto et al. (2004) seminumerical model for reionization. Zahn et al. 2006.
Things to understand from percolation theory: Reionization, Spread of metals and so on
Neal Dalal:
Spherical collapse
Ellipsoidal collapse (Bond and Myers 1996) collapse of uniform isolated sphere including a background tide. Unclear what to do after first axis collapses. The collapse occurs later than spherical collapse.
Collapse of a scale free non-spherical profile.
\delta rho \propto r^{-gamma} f(theta,phi)
The solution is self similar. Things at different r will go through similar phases at different times.
BBKS (1986):
Npeak(nu), triaxiality, initial radial density profile.
n(>M) = int de \int_{pc}^{\infty} dp dnu N(e,p,nu,M)
FOF dn/dM for \Omega_m=1, P(k) \propto const., this model works perfectly but the fitting functions break down.
Adiabatic invariants if the potential changes slowly compared to orbital time.
The radial action J_r = \int v_r dr
M_L r_{ta} is the adiabatic invariant.
Matteo Viel
Neutrino effects on the power spectrum of total matter: Check the latest arxiv paper.
High redshift voids also get affected. Navarro-Villaescusa 2011
Highlights section:
Nikhil Padmanabhan: reconstructing the BAFs in redshift space and projected space separately.
Tijana: Primordial abundances are not all hunky dory yet.
Jasche and Wandelt 2011: Interesting idea to reduce the error on photoz-s by an order of magnitude.
Adam Lidz and co: CO intensity mapping and cross correlating with the 21 cm signal to confirm high-z nature of both signals.
Martin White: Modelling of the 3d lyman alpha forest.