Lyman-alpha forest and Primordial Non-gaussianities (fnl) with - - PowerPoint PPT Presentation

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Lyman-alpha forest and Primordial Non-gaussianities (fnl) with - - PowerPoint PPT Presentation

Feb 03, 2023 300 likes •663 views

Lyman-alpha forest and Primordial Non-gaussianities (fnl) with collaborators: Anze Slosar, Uros Seljak and Vincent Desjacques Shirley Ho Lawrence Berkeley Lab 18 Sep 2009, Paris-Berkeley meeting Outline What is fnl? What have we

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Lyman-alpha forest and Primordial Non-gaussianities (fnl)

with collaborators: Anze Slosar, Uros Seljak and Vincent Desjacques Shirley Ho Lawrence Berkeley Lab 18 Sep 2009, Paris-Berkeley meeting

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Outline

  • What is fnl?
  • What have we done with LSS and fnl?
  • What can we do with Lya and fnl?

—Lya flux spectra with different non-gaussianities —How about with redshift space distortions?

  • Things to worry about:

—UV background fluctuations —Continuum subtractions ...

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Lyman Alpha Forest: what is it?

Time Redshift

z~0 z~6 z~1100

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Lyman Alpha Forest: what is it?

Time Redshift

z~0 z~6 z~1100 Courtesy simulation of gas from Renyue Cen and Jerry Ostriker

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Lyman Alpha Forest: what is it?

Time Redshift

z~0 z~6 z~1100

Courtesy image from Joanne Cohn’s website

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Lyman Alpha Forest: what is it?

Time Redshift

z~0 z~6 z~1100

λ(˚ A)

Flux

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Lyman Alpha Forest: what is it?

Time Redshift

z~0 z~6 z~1100

Locates the Neutral Hydrogen, thus

  • verdensities of the Universe.

λ(˚ A)

Flux

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V (φ)

Φ = φ + fNLφ2

parameterize how much non-linear corrections are there to the potential

What is fnl?

—Non-gaussianities in Early Universe Inflation

reheating

Primordial potential (assumed to be gaussian random field)

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V (φ)

Φ = φ + fNLφ2

parameterize how much non-linear corrections are there to the potential

What is fnl?

—Non-gaussianities in Early Universe Inflation

reheating

Primordial potential (assumed to be gaussian random field)

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Stolen from Ben Wandelt

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Stolen from Ben Wandelt

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Stolen from Ben Wandelt

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Stolen from Ben Wandelt

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Stolen from Ben Wandelt

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curvaton models, DBI inflation canonical inflation

Slosar et al. 2008

ghost inflation

Best current CMB measurement

What have we done with LSS and fnl?

—Non-gaussianities in Early Universe

fNL fNL

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Lyman Alpha Forest: what can it do?

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Lyman Alpha Forest: what can it do?

Ωm = 0.25, ΩΛ = 0.75, h = 0.75, n = 0.97, σ8 = 0.8 10243particles, Lbox = 1.6Gpc/h

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Lyman Alpha Forest: what can it do?

Ωm = 0.25, ΩΛ = 0.75, h = 0.75, n = 0.97, σ8 = 0.8

Fluctuating Gunn Peterson approximation

τ = A(1 + δ)β F = e−τ 10243particles, Lbox = 1.6Gpc/h

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Lyman Alpha Forest: what can it do?

  • Primordial Non-gaussianities via Lyman alpha forest

Skewers of Neutral Hydrogen

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Lyman Alpha Forest: what can it do?

Skewers of Neutral Hydrogen Take the 3D power-spectrum of these skewers!

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P(k) (Mpc/h)^3 k (h/Mpc)

Courtesy slide from Anze Slosar

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PfNL PfNL=0 − 1

What can we do with Lya and fnl?

  • 0.3
  • 0.2
  • 0.1

0.1 0.2 0.3 0.4 0.01 0.1 P_fnl(k)/P_fnl=0(k) -1 k (h/Mpc) fnl = -100 fnl = +100

fnl = -100 fnl = +100 Ho, Slosar, Seljak & Desjacques (in prep)

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PfNL PfNL=0 − 1

What can we do with Lya and fnl?

fnl = -100 (z-space) fnl = +100 (z-space) Ho, Slosar, Seljak & Desjacques (in prep) With z-space distortions!

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curvaton models, DBI inflation canonical inflation ghost inflation

BOSS LRG only constraints

Ho, Slosar, Seljak & Desjacques (in prep)

BigBOSS Ly-alpha forest constraints Planck forecasted constraints

What can we do with Lya and fnl?

—Non-gaussianities in Early Universe Best current CMB measurementfNL

∆(fNL) ∼ 5 ∆(fNL) ∼ 1 ∆(fNL) = 18

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Other things we should worry about:

  • UV background fluctuations
  • continuum subtractions
  • others?
  • There maybe easy solutions:

—Using multiple tracers! —Quasars, LRGs, Lyman-alpha forest (but in different ways)

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Lyman Alpha Forest: what else can it do?

  • Dark Energy via Baryon Acoustic Oscillations

—the correlation function:

ξf(r) =< δf(ˆ x)δf(ˆ x + ˆ r) >

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Lyman Alpha Forest: what can it do?

  • Dark Energy via Baryon Acoustic Oscillations

—the correlation function:

ξf(r) =< δf(ˆ x)δf(ˆ x + ˆ r) >

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Lyman Alpha Forest: what can it do?

  • Dark Energy via Baryon Acoustic Oscillations

—take the correlation function:

ξf(r) =< δf(ˆ x)δf(ˆ x + ˆ r) >

r (h/Mpc) Flux Real (Redshift) Space Correlation function What acoustic peak would look like if we use Lya forest flux!

r2ξ(r)

Slosar, Ho, White & Louis (2009)

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Lyman Alpha Forest: what can it do?

r (h/Mpc)

r2ξ(r)

Real Space Correlation function Redshift Space Correlation function

Scaled matter correlation functions Slosar, Ho, White & Louis (2009)

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Conclusions

  • We can probe early universe with Lya forest!
  • z-space distortions? not a problem!
  • Other things Lya forest can do?

—BAO -> Dark energy at high-z —neutrino mass constraints (small scale P(k)) —IGM physics...

  • We need to worry about systematics such as:

—UV background fluctuations —continuum fluctuations, etc

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Checking my Lya-P(k)

\

kP(k)/π

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What does fnl do?

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What does fnl do?

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0.6 0.7 0.8 0.9 1 1.1 1.2 0.001 0.01 0.1 1 P_F(k) (Mpc/h)^3 k (Mpc/h)^{-1} z-space distorted flux P(k) fnl=-100 z-space distorted flux P(k) fnl=+100

What about z-space distortions?

k (h/Mpc) P(k) [Mpc/h]^3