Course Project
The Values of Cosmic Parameters
H0 | q0 | T0 |
Ωm | ΩΛ |
Ωb | fb | σ8 | ns | r | AL
The class project is a joint effort to compile observational constraints on
the values of the fundamental cosmological parameters.
Each of you will choose a cosmological parameter
on which to report. Which one is up to you, but you must discuss your
choice with the instructor in advance.
Some examples of possible topics are given below.
There should be a bottom line, like H0 = 70 or
Ωm = 0.25 (along with error bars, of course).
You will make a 15 minute oral presentation to the class.
Write an abstract (1 paragraph) on the result as if you were
the author of the paper who is going to present it at a meeting.
The written abstract is
intended for the other conference attendees - in this case, your classmates -
and are due Friday December 2 so that the can be posted in advance of you
talks on Tuesday December 6.
I will post them so that your audience can read them in advance
like abstracts at a conference.
Topics to Investigate: Observational Constraints
The goal is to learn about observational constraints on cosmological
parameters. E.g.,
- H0 from direct measurements (e.g., Riess et al. (2019)
- Age constraints [f(q0,1/H0)] from globular clusters
(e.g., Valcin et al. (2020)
- Ωb from the light element abundances
(e.g., deuterium,
helium,
lithium)
- Ωm from
- kinematics
- large scale structure (e.g., 2dF;
6dF);
- cluster baryon fractions (e.g., Evrard)
- cluster mass-to-light ratios (e.g., CNOC)
- See the more general list of topics below
for more ideas.
Note that observational constraints often boil down to a statement
like "Ωbh2 = 0.019 +/- 0.001." This is the
essence of what you're after, though of course you need to understand the
method in order to appreciate how the result is obtained and what might go
wrong. But we will need something like this as a bottom-line answer for
intercomparison of results in the culminating discussion.
More Topic Ideas
Parameter Estimation
- Hubble Constant, Specific Distance Indicators and their Calibration
- Age (globular clusters, high-z galaxies, nucleochronology, etc.)
- Omega
- Deceleration (see also classic tests)
- Lambda
- "Concordance"
Classic Tests
- Standard Candle (e.g., SN Ia)
- Standarad Rod (e.g., radio lobes)
- Count-magnitude
- Count-redshift
- Tolman test
Large Scale Structure
- Voids, Walls & Filaments
- Bulk Flows
- Clusters (abundance, bias, baryon fraction, gravitational lensing, etc.)
- Power Spectrum; Shape Parameter
- Structure at High Redshift
- The Hubble Deep Field(s)
Microwave Background
- Power Spectrum
- Temperature measurements; dipole and quadrupole
- Space missions, past & present: COBE, MAP, & PLANCK
- Structure Formation
- Joint cosmic parameter estimation, "cosmic complimentarity"
Primordial, or Big Bang Nucleosynthesis (BBN)
- Deuterium from QSO absorbers
- Helium from HII Regions
- Lithium from metal poor stars
Dark Matter
- Hot Dark Matter (e.g., massive neutrinos)
- Cold Dark Matter (WIMPs, Axions; structure formation)
- Baryonic Dark Matter (missing baryons; brown dwarfs, MACHOs)
- Alternatives to Dark Matter (conformal Weyl gravity, MOND)
Alternative Cosmologies
for the bold and brave
- Steady State
- Chronometric
- Plasma
- MOND
- Weyl
- Brans-Dicke
- Quintessence, X-matter