# Presentation: 602897

## Opening Thoughts

**Wendy Freedman**
**Carnegie Observatories, Pasadena**** CA**
**Chicago, September 2002**

**COSMO-02**

## Dear Wendy and David:
Cosmo-02 has proven even more popular than we had anticipated... Your two presentations constitute the opening and closing of the conference,... we are asking you for a combination of judgment, advice, inspiration and prognostication for its practictioners. 

**Cosmo-02 has proven even more popular than we had anticipated... Your two presentations constitute the opening and closing of the conference,... we are asking you for a combination of judgment, advice, inspiration and prognostication for its practictioners. **

**Goals set by our friendly Organizing Committee...**

**And I’ll tell you what the dark energy is...**

## Dear Wendy and David:
Cosmo-02 has proven even more popular than we had anticipated... Your two presentations constitute the opening and closing of the conference,... we are asking you for a combination of judgment, advice, inspiration and prognostication for its practictioners. 
 (In particular we are *not* looking for an overview or summary – give us your personal point of view.) The talks are short (25 minutes...) and we realize that we are asking you to do the nearly impossible. 
We trust that all of our speakers will make an extra effort to come as close as possible to the unrealistic goals we have set for them.

Sincerely,

**Cosmo-02 has proven even more popular than we had anticipated... Your two presentations constitute the opening and closing of the conference,... we are asking you for a combination of judgment, advice, inspiration and prognostication for its practictioners. **
** ****(In particular we are *not* looking for an overview or summary – give us your personal point of view.) The talks are short (25 minutes...) and we realize that we are asking you to do the nearly impossible.**** **
**We trust that all of our speakers will make an **_**extra effort to come as close as possible to the unrealistic goals we have set for them.**_
**Sincerely,**

**Goals set by our friendly Organizing Committee...**

## Successes:

**Inflation, gravitational instability plus cold   dark matter...**
** **

## Power Spectrum

_**Power Spectrum**_

******~ ********m****h ~ 0.25  ****§****   0.05**

**Primordial power spectrum:**
**  ****P(k) ****/**** k****n  **** (n=1 scale invariant)**

** ****2dFGRS**

**Tegmark**
**  ****(2002) **

## CMB Anisotropies

**************1.03 ****§**** 0.03**

**flat geometry**

**T****0 ****= 2.725****  ****§**** 0.001K**

** ****n = 1.05  ****§**** 0.06**

**Dasi, Boomerang, MAXIMA, CBI**

**Notes:**
Astro ph 0201137 Masi et al. 

## Troubles: Inflation + Cold Dark Matter

_**Troubles: Inflation + Cold Dark Matter**_

**poor fit to galaxy power spectrum for Einstein-de Sitter model**
**    ****(SCDM: ********m**** = 1, ******** = 0, h = 0.5)**
**2.****  ****predicts excess of small satellites**
**3.  predicts central cusps in density profiles**

**Moore et al**. **1999**

**Moore et al**.

**2.   Numbers of satellites**

**3. Cuspiness of profiles**

**}**

**  ****on small scales**

**model**

**data**

**SCDM**

******CDM**

**OCDM**

******CDM**

**   ****Jenkins et al. (1997)        **

**1. Power spectrum**

## Neils Bohr

**“****How wonderful that we have met with a paradox. Now we have some hope of making progress.”**
**                                  **

**-Neils Bohr**

## Taking Stock of Where We Are

** ****CDM simulations fail to fit distribution of galaxies on**
**         ****large scales**
** ****no evidence for ********m**** = 1**
** ****age discrepancy**

**Open universe fails because:**

**Einstein-de Sitter model fails because:**

** ****CMB anisotropies yield ********0**** = 1**

** ****Variants to CDM:**
**   ****Hot dark matter fails because:**
** ****free streaming wipes out seeds for structure formation**

**Galaxy kinematics**

**X-ray gas**

**Lensing**

**Cluster baryons**

******m**** ~ 0.3**

## Taking Stock of Where We Are

**Lambda CDM universe current winner because:**

** ****excellent fit to galaxy power spectrum on large scales**
** ****consistent with faint supernovae at high redshifts**
** ****resolves age discrepancy**
** ****consistent with LSS+CMB anisotropy results**
** ****no single point failure**

**... ****and no better alternatives!**

## Inflation + Cold Dark Matter+  Dark Energy

_**Inflation + Cold Dark Matter+  Dark Energy**_

**2Df Power Spectrum **
**      ****+ ******** CDM**

** ****from Percival et al. 2001**

**CMB**

**Supernovae**

**H****0 ****Key**
**Project**

******m ****= 0.3**
********** ****= 0.7**
** ****h   = 0.7**

**Notes:**
Power spectrum – with 2df data and LCDM model  - from Frenk 0208219, adapted from Percival et

## Critical Missing Pieces to the Current “Standard Model”

**Cold dark matter dominates the matter density ****and is in an unknown form**
**The overall mass-energy density is dominated by dark energy, ****for which there is currently no explanation**
** ****The dynamics of inflation depends on particle physics at high energy, ****and nothing is known of the hypothetical scalar field that drives inflation**

## The Challenge:

_**The Challenge:**_

**1. Why the small value?**

**2. Why now?**

**Observed:                         ******** ****·**** 10****-30**** g cm****-3**
**Quantum field theory:    ********  = ****1**
**Quantum gravity:            ******** ****·**** 10****+90**** g cm****-3**
**Supersymmetry:              ******** ****·**** 10****+30**** g cm****-3**

**Planck**

** ****EW**

**BBN**

**NOW**

**              **

** ****log(a)**

** **

**Carroll (2001)**

**          **********

**“****The mystery of the**
**cosmological constant  is    probably the most pressing obstacle to significantly improving the models of elementary particle physics derived from string theory.”**
** **
**                     ****Witten (2000)**

##  : Blunder, Convenient, or Correct?

** ****1900                  1920                  1940                  1960                1980                  2000**
**                                                          ****Year**

**  ****SN1a**
**  ****CMB**

**Freedman (2000)**

## Cosmological Framework

****** ****= ********b**** + ********CDM**** + ************ + ********rad ****+ ********X ****+...**

******0**** **** ́**** ******** / ********crit **
******crit  ****= **3H02/8G

- _Cosmological Framework_

**Essential to determine equation of state for**
**dark energy:**

## Cosmological Framework

**Essential to determine equation of state for dark energy :**

****** ****= ********b**** + ********CDM**** + ************ + ********rad ****+ ********x ****+...**

******0**** **** ́**** ******** / ********crit **
******crit  ****= **3H02/8G

- _Cosmological Framework_

** ****w =  P(z) / ********z)**

** ********z) ****/ ****(1 + z)****3(1+w)**

**Matter:      ********m**** ****/**** (1+z)****3****     w = 0**
**Radiation: ********r****  ****/**** (1+z)****4****     w = 1/3**
**Vacuum:    ************ ****/**** (1+z)****0****     w = -1**

## 16 Cosmological Parameters

** **_**first set**_**: 10 parameters describing FLRW model**
**      ****-- the expansion**
**      ****-- global geometry**
**      ****-- age**
**      ****-- composition  **
**                    ****H****0****, q****0****, w, t****0****, T****0****, ********0****, ********b****, ********CDM****, ************, ********x**

_**2 sets of parameters:**_

** **_**second set**_**: 6 parameters describing the **
**                      ****deviations from exact homogeneity**
**                      ****S, T, ********8**** , n, n****T ****, dn/d ln k**

**Freedman & Turner (Science, 2002)**

## Table of Cosmological Parameters

_**Part I: 9 global FLRW parameters:**_

**Freedman & Turner (Science, 2002)**

|  H0 |  72§7km/sec/Mpc | Present expansion rate |
| --- | --- | --- |
|  q0 |  -0.67 § 0.25 | Deceleration parameter |
|   t0 |  13 § 1.5 | Age of the Universe |
|  T0 |  2.725 § 0.001K | CMB temperature |
|  0 |  1.03 § 0.03 | Density parameter |
| b |  0.039 § 0.008 | Baryons |
|  CDM |  0.3 § 0.05 | CDM |
|   |  0.002 – 0.05 | Massive neutrinos |
|  X |  0.7 § 0.1 | Dark energy |

**Notes:**
Second set: at early times deviations were small and today they manifest themselves in the observed LSS

## Table of Cosmological Parameters

_**Part II: 6 fluctuation parameters:**_

**Freedman & Turner (Science, 2002)**

|  S |  10-10  | Scalar amplitude |
| --- | --- | --- |
|  T |  < S | Tensor amplitude |
|  8 |  0.9 § 0.1 | Mass fluctuations (8 Mpc) |
|  n |  1.05 § 0.09 | Scalar index |
|  nT |  ------ | Tensor index |
|  dn/d ln k |  -0.02 § 0.04 | Running of scalar index |

## CMB Anisotropies

**Robust measure of ********0**** **
**But large degeneracies**

**H****0****=70**

**Lineweaver (2001)**

** ****Can have same geometry, but very   different matter content**
**To break degeneracies: ****H****0****, SNIa, galaxy power spectrum, weak lensing**** **
** ****CMB measurements give  no    information  on w(z)**

******m**** and ************are not measured **
**     ****independently from the CMB alone.**

## Angular power spectrum

**expected **
**precision**

_**Angular power spectrum**_

## Constraining Quintessence

**Solid line: w****q**** = -0.8**
**Dashed line: w**** ****= -1**
**A Challenge!!!**

**Best fit: ****w****q**** = -0.8**
**              ********q****  ****= 0.72**

**Baccigalupi et al. 2001**

## Prognostication***

***** ****Beware of observers willing to tell**
**  ****the future....**

**Einstein will turn out**
** ****to be right about the**
** ****cosmological constant**

## Prognostication***

***** ****Beware of observers willing to tell**
**  ****the future....**

**Einstein will turn out**
** ****to be right about the**
** ****cosmological constant**

**Either way!...**

**R********–1/2****R****g********= 8********GT********+ ********g******

**“****My biggest blunder”**

## Looking Ahead

_**Looking Ahead**_

**CERN**

**CDMS  in the Soudan mine**

**COBE**

**Predicted Planck**

**LISA orbit**

**SNAP**

**Fermilab**

**Planck**

**OWL – 100m telescope**

**   **

**CMB Polarization**

**Direct expansion**
** ****rate: 2 m/s/century!**

**LHC prototype**
**  ****beam collider**

**Cyclic**
**Branes**
**   ****???**

## Magellans I and II domes

**The Magellan Telescopes**

**Carnegie**
**Harvard**
**MIT**
**Arizona**
**Michigan**

**Las Campanas, Chile**

## Carnegie/Las Campanas Infrared SN Survey

**3 telescopes, coordinated**
**       ****followup, 5 years **

**Carnegie/Las Campanas Infrared SN Survey******

**Hamuy et al. (2001)**

**>300 6.5m Magellan**
**nights (2003-2008)**

**Infrared Hubble diagram**

**Decline-rate relation**

** ****H-band may**
** ****be insensitive**
** ****to decline rate**

## Carnegie Centennial Lectures

**Carnegie Centennial **
**    ****Symposium**

**Measuring and Modeling **
**      ****the Universe**

**http://www.ociw.edu/ociw/symposia/symposium2**

**November 18-22, 2002**
**Pasadena, CA**

**Malcolm Longair         John Schwarz**
**Lisa Randall                 Michael Turner**
**Alan Guth                     Steven Weinberg**
**Marc Kamionkowski  Wendy Freedman**
**John Carlstrom           Chris Kochanek**
**John Tonry                  Joe Silk**
**David Spergel              Andrew Lange**
**Matias Zaldiarraga     Tony Readhead**
**Lyman Page                 Sandy Faber**
**Roger Blandford         Alex Filippenko**

## Are We Living in a Golden Age?

## Are We Living in a Golden Age?

**Or are we still living in a **
**   ****Bronze Age?...**

## Are We Living in a Golden Age?

**Or are we still living in a **
**   ****Bronze Age?...**

**Or taken to epicycles?...**

## Are We Living in a Golden Age?

**Or are we still living in a **
**   ****Bronze Age?...**

**Let us look forward**
** ****to an Age of Reason**
** ****and understanding!...**