Introduction

Below I give a syllabus for the unit, together with guidance as to where you can find the relevant material. More detailed advice on how to approach the work is given in the introduction to Unit 1 , and will not be repeated here. You should aim to spend about 12 hours on the unit, plus a further 4 hours for the assessed exercise (quite a lot of which relates back to Unit 2). This unit is conceptually less challenging than the last one, but parts of it are really not covered at all adequately by either of the course books, and the field of galaxy formation is moving very fast. My 1st lecture gives you an overview of these topics and my 2nd lecture is intended to introduce you to the topic of structure formation.

Syllabus and source

In this unit we study the major stages in the evolution of the Universe after the Big Bang, taking them in chronological order. We pass quickly over the exotic early phases, but look at the emergence of macroscopic structures. The online copy of Bothun's book provides useful detailed discussion, to supplement the rather sketchy treatment of some of these issues in Liddle and Rowan-Robinson. Finally, you should spend a little time browsing through some of the links to cosmological simulation pages, to get a feel for the impact which such studies are making on our understanding of the evolution of the Universe - I will say more about this in the Unit 3 lecture. The lecture will be found here and here.

 
Topic Sources Comments
Particle  horizon:
    Concept  - the observable Universe		 RR(4.10)
 The particle horizon is often referred to simply as "the horizon".
Horizon and flatness problems:
   Problems of the Big Bang model:
   Flatness - why is Omega close to 1 ? 
   Horizon  - unconnected regions have same CMB temperature		 L1(12.1), L2,L3(13.1),  RR(p.161-2)  
Inflation:
    Early rapid exponential expansion 
    Solves horizon & flatness problems 
    May be due to a phase of high vacuum energy density
 L1(12.2-12.5), L2,L3(13.2-13.5) RR(5.4),  NW(Part 4)  See sections I-III of the  Guth paper for more detail 
Evolution of density and temperature:
    Effect of expansion on density and temperature
    Differing behaviour of matter & radiation - matter and radiation dominated eras
 RR(5.1 & 5.2) , L1(9.1, 10), L2,L3(10.1,11) See especially RR Figs. 5.2 & 5.3
Cosmic nucleosynthesis: 
    Key reactions 
    Origin of the helium fraction
    Why are only light elements synthesised?
RR(5.3), L1(11), L2,L3(12)
Add to  your notes from Unit 1 - this time tracing the key reaction stages.
Recombination (decoupling):
    What is this, when and why did it happen?		 RR(5.2), L1(9.3) , L2,L3(10.3-10.4)  
Growth of structure
    From CMB fluctuations to today's galaxies 
    Growth of density perturbations
    Collapse and virialisation
    Hierarchical merging
    Jeans mass   and the effects of pressure  on baryons
RR(5.5,6.1-6.2), L1(13),L2,L3(A5.2, A5.4), B(3.1,  4.1, 5.1-5.3),Unit 3 lecture

Major section - see detailed guidance here.
Galaxy formation
    Cooling of baryons
    Monolithic collapse and hierarchical models
    
Unit 3 lecture, RR(2.5)
Detailed treatments in papers by Ellis (observational), and Baugh, Silk and Cole (theoretical modelling).
 R-R gives only a little on this important topic, and Liddle almost nothing. The papers referred to here are more detailed than you need, but you could usefully skim through some of them.
Cosmological simulations
    Growth of large-scale structure depends on  cosmological  parameters		 VIRGO, Local volume Note that some simulations include only dark matter.

Notes

  1. Key: RR=Rowan-Robinson, L1=Liddle 1st Edition, L2= Liddle 2nd edition, L3=Liddle 3rd edition, NW=Ned Wright's pages, B=Bothun - relevant sections are given in brackets.
  2. The topics listed are not of equal size.
  3. References given are not by any means the only ones (e.g. check out some of the suggested reading material and other references) but they should provide a reasonable treatment.
  4. For the more complex topics (such as the distance scale) it pays to consult several sources and to synthesise the results. This takes longer, but should result in a better understanding.

Unit 3: Evolution from the Big Bang

Introduction 
Syllabus and sources 
Self-test problems 

Units

  1. The Hot Big Bang
  2. Cosmological theory
  3. Evolution from the Big Bang
  4. Dark matter & baryons
  5. Observational properties and cosmological tests 

Contact

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Office: Physics West, 223