## Inflation and the accelerating universe

*Ta-Pei Cheng*

### in Relativity, Gravitation and Cosmology: A Basic Introduction

- Published in print:
- 2009
- Published Online:
- February 2010
- ISBN:
- 9780199573639
- eISBN:
- 9780191722448
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199573639.003.0011
- Subject:
- Physics, Particle Physics / Astrophysics / Cosmology

Einstein introduced the cosmological constant in his field equation so as to obtain a static universe solution. This constant energy density corresponds to a negative pressure, giving rise to a ... More

## GR as a geometric theory of gravity — II

*Ta-Pei Cheng*

### in Relativity, Gravitation and Cosmology: A Basic Introduction

- Published in print:
- 2009
- Published Online:
- February 2010
- ISBN:
- 9780199573639
- eISBN:
- 9780191722448
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199573639.003.0014
- Subject:
- Physics, Particle Physics / Astrophysics / Cosmology

The mathematical realization of equivalence principle (EP) is the principle of general covariance. General relativity (GR) equations must be covariant with respect to general coordinate ... More

## Exploring the Universe With a Microscope

*Gian Francesco Giudice*

### in A Zeptospace Odyssey: A Journey into the Physics of the LHC

- Published in print:
- 2009
- Published Online:
- February 2010
- ISBN:
- 9780199581917
- eISBN:
- 9780191723001
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199581917.003.0012
- Subject:
- Physics, Particle Physics / Astrophysics / Cosmology

Results from the LHC can expand our knowledge of the early stages of the universe. The connection between the world of particle physics and the structure of our universe is probably one of the most ... More

## The cosmological constant problem: why it’s hard to get dark energy from microphysics

*C. P. Burgess*

### in Post-Planck Cosmology: Lecture Notes of the Les Houches Summer School: Volume 100, July 2013

- Published in print:
- 2015
- Published Online:
- March 2015
- ISBN:
- 9780198728856
- eISBN:
- 9780191795794
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198728856.003.0004
- Subject:
- Physics, Particle Physics / Astrophysics / Cosmology

This chapter presents an introduction to “naturalness” problems in cosmology and the cosmological constant problem in particular. The main focus is the “old” cosmological constant problem, although ... More

## Casimir Effect and Vacuum Energy

*VOLOVIK GRIGORY E.*

### in The Universe in a Helium Droplet

- Published in print:
- 2009
- Published Online:
- January 2010
- ISBN:
- 9780199564842
- eISBN:
- 9780191709906
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199564842.003.0029
- Subject:
- Physics, Condensed Matter Physics / Materials, Particle Physics / Astrophysics / Cosmology

This chapter opens the part of the book devoted to quantum vacuum in non-trivial gravitational background and to vacuum energy. There are several macroscopic phenomena, which can be directly related ... More

## Believing the Big Bang

*Peter Coles*

### in From Cosmos to Chaos: The Science of Unpredictability

- Published in print:
- 2006
- Published Online:
- January 2010
- ISBN:
- 9780198567622
- eISBN:
- 9780191718250
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198567622.003.0008
- Subject:
- Physics, Theoretical, Computational, and Statistical Physics

Cosmology aims to build a coherent unified description of the entire universe as a single system. This means not just the disposition of everything that exists at a particular time, but also how this ... More

## Gravity

*VOLOVIK GRIGORY E.*

### in The Universe in a Helium Droplet

- Published in print:
- 2009
- Published Online:
- January 2010
- ISBN:
- 9780199564842
- eISBN:
- 9780191709906
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199564842.003.0002
- Subject:
- Physics, Condensed Matter Physics / Materials, Particle Physics / Astrophysics / Cosmology

This chapter discusses the Einstein theory of gravity, which consists of two main elements: (1) gravity is related to a curvature of space-time in which particles move along geodesic curves; and (2) ... More

## Microscopic Physics of Quantum Liquids

*VOLOVIK GRIGORY E.*

### in The Universe in a Helium Droplet

- Published in print:
- 2009
- Published Online:
- January 2010
- ISBN:
- 9780199564842
- eISBN:
- 9780191709906
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199564842.003.0003
- Subject:
- Physics, Condensed Matter Physics / Materials, Particle Physics / Astrophysics / Cosmology

There are two ways to study quantum liquids. One is the fully microscopic treatment, which can be realised either by numerical simulations of the many-body problem, or for some special ranges of the ... More

## The General Relativistic Framework for Cosmology

*Ta-Pei Cheng*

### in A College Course on Relativity and Cosmology

- Published in print:
- 2015
- Published Online:
- August 2015
- ISBN:
- 9780199693405
- eISBN:
- 9780191803130
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199693405.003.0008
- Subject:
- Physics, Particle Physics / Astrophysics / Cosmology

Cosmology is the study of the universe as one physical system. The discovery by Hubble and Lemaître that the universe is expanding suggested strongly that it had a beginning. The age is estimated ... More

## Problems with the Cosmological Constant Problem

*Adam Koberinski*

### in Philosophy Beyond Spacetime: Implications from Quantum Gravity

- Published in print:
- 2021
- Published Online:
- September 2021
- ISBN:
- 9780198844143
- eISBN:
- 9780191879777
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780198844143.003.0012
- Subject:
- Philosophy, Metaphysics/Epistemology

The cosmological constant problem is widely viewed as an important barrier and hint to merging quantum field theory and general relativity. It is a barrier insofar as it remains unsolved, and a ... More

## Inflation and the Accelerating Universe

*Ta-Pei Cheng*

### in A College Course on Relativity and Cosmology

- Published in print:
- 2015
- Published Online:
- August 2015
- ISBN:
- 9780199693405
- eISBN:
- 9780191803130
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199693405.003.0010
- Subject:
- Physics, Particle Physics / Astrophysics / Cosmology

The universe experienced a huge expansion in the earliest moments of the big bang. This cosmic inflationary epoch (with a large cosmological constant) can provide the correct initial conditions for ... More

## Albert Einstein’s Finite Universe

*Helge Kragh*

### in Masters of the Universe: Conversations with Cosmologists of the Past

- Published in print:
- 2014
- Published Online:
- March 2015
- ISBN:
- 9780198722892
- eISBN:
- 9780191789564
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198722892.003.0005
- Subject:
- Physics, History of Physics, Particle Physics / Astrophysics / Cosmology

The interview with Einstein took place in 1928 in his apartment in Berlin. Einstein explained how he came to his cosmological theory of 1917 in which he applied general relativity to the universe at ... More

## Willem de Sitter and the Expanding Universe

*Helge Kragh*

### in Masters of the Universe: Conversations with Cosmologists of the Past

- Published in print:
- 2014
- Published Online:
- March 2015
- ISBN:
- 9780198722892
- eISBN:
- 9780191789564
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198722892.003.0006
- Subject:
- Physics, History of Physics, Particle Physics / Astrophysics / Cosmology

The interview with the eminent Dutch astronomer Willem de Sitter took place in Leiden in 1933, at a time when the expanding universe was accepted by many astronomers. De Sitter looked back to the ... More

## Alternative Gravitational Theories

*John W. Moffat*

### in The Shadow of the Black Hole

- Published in print:
- 2020
- Published Online:
- June 2020
- ISBN:
- 9780190650728
- eISBN:
- 9780197517383
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780190650728.003.0009
- Subject:
- Physics, Particle Physics / Astrophysics / Cosmology

There have been many proposed modifications of gravitational theory, beginning with Einstein’s general relativity, modifying Newtonian gravity, and Weyl’s attempt at unifying gravity and ... More

## Introduction: Gut and Anti-Gut

*VOLOVIK GRIGORY E.*

### in The Universe in a Helium Droplet

- Published in print:
- 2009
- Published Online:
- January 2010
- ISBN:
- 9780199564842
- eISBN:
- 9780191709906
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199564842.003.0001
- Subject:
- Physics, Condensed Matter Physics / Materials, Particle Physics / Astrophysics / Cosmology

The book studies relations of condensed matter with particle physics and cosmology. The fundamental links between cosmology and particle physics have been well established and is widely exploited in ... More

## The induced gravity approach

*Iosif L. Buchbinder and Ilya L. Shapiro*

### in Introduction to Quantum Field Theory with Applications to Quantum Gravity

- Published in print:
- 2021
- Published Online:
- April 2021
- ISBN:
- 9780198838319
- eISBN:
- 9780191874666
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780198838319.003.0022
- Subject:
- Physics, Particle Physics / Astrophysics / Cosmology, Theoretical, Computational, and Statistical Physics

This short chapter includes a general review and analysis of the induced gravity approach. Induced gravity is regarded as one way of resolving the contradiction between renormalizability and the ... More

## Observational support for the standard model

*Hans Ringström*

### in On the Topology and Future Stability of the Universe

- Published in print:
- 2013
- Published Online:
- September 2013
- ISBN:
- 9780199680290
- eISBN:
- 9780191760235
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199680290.003.0005
- Subject:
- Mathematics, Mathematical Physics, Geometry / Topology

In 1998–1999, our perception of the universe underwent a dramatic change. The observations of supernovae of type Ia led to the conclusion that our universe is expanding at an accelerating rate. One ... More

## Asymptotics

*Hans Ringström*

### in On the Topology and Future Stability of the Universe

- Published in print:
- 2013
- Published Online:
- September 2013
- ISBN:
- 9780199680290
- eISBN:
- 9780191760235
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199680290.003.0032
- Subject:
- Mathematics, Mathematical Physics, Geometry / Topology

In Chapter 32, we derive detailed asymptotics of the solutions constructed in Chapter 31. We separate between the two cases that the scalar field is zero and non-zero. The case of zero scalar field ... More

## The Crash

*Alvaro De Rújula*

### in Enjoy Our Universe: You Have No Other Choice

- Published in print:
- 2018
- Published Online:
- February 2020
- ISBN:
- 9780198817802
- eISBN:
- 9780191859366
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780198817802.003.0036
- Subject:
- Physics, Particle Physics / Astrophysics / Cosmology

Quantum Mechanics plays a role in our understanding of the extremely large and small realities, Why the measured cosmological constant has such an “unnatural” value. Natural numbers in a physical ... More

## Riemann and Einstein

*Moataz H. Emam*

### in Covariant Physics: From Classical Mechanics to General Relativity and Beyond

- Published in print:
- 2021
- Published Online:
- May 2021
- ISBN:
- 9780198864899
- eISBN:
- 9780191897313
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780198864899.003.0007
- Subject:
- Physics, Condensed Matter Physics / Materials, Theoretical, Computational, and Statistical Physics

In this chapter we make notions of spatial and spacetime curvature more precise by presenting Riemann’s theory of non-Euclidean spaces. We then construct Einstein’s gravitational field equations and ... More