Abstract
FLRW spacetimes are much simpler than black hole spacetimes but still contain horizons. Cosmological horizons have been studied in inflationary scenarios of the early universe. In general, FLRW spaces contain time-dependent apparent horizons expressed by simple equations. This chapter discusses such cosmological apparent horizons and their dynamics.
Simplicity is the ultimate sophistication.
—Leonardo da Vinci
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Notes
- 1.
Also called “r-gauge” (e.g., [30]).
- 2.
As in most situations, the integrating factor is not unique.
- 3.
The coordinate system in which the metric assumes the form (3.21) is sometimes referred to as Nolan gauge in the literature. Nolan [69–71] studied this coordinate system in the case of the McVittie metric [61] representing a central object embedded in a FLRW universe, eventually restricting to k = 0 or − 1. The McVittie metric reduces to that of Eq. (3.21) in the limit in which the mass of the central object vanishes, hence (3.21) is a trivial case of the McVittie line element in the Nolan gauge.
- 4.
- 5.
- 6.
More realistically, photons propagate freely in the universe only after the time of the last scattering or recombination, before which the Compton scattering due to free electrons in the cosmic plasma makes it opaque. Therefore, cosmologists introduce the optical horizon with radius \(a(t)\int _{t_{ \text{recombination}}}^{t} \frac{dt'} {a(t')}\) [66]. However, the optical horizon is irrelevant for our purposes and will not be used here.
- 7.
The notation for the proper radius \(R \equiv a(t)r = a(t)f(\chi )\) is consistent with our previous use of this symbol to denote an areal radius because a(t)r is in fact an areal radius, as is obvious from the inspection of the FLRW line element (3.10). If \(k\neq 0\), the proper radius \(a(t)\chi\) and the areal radius \(a(t)f(\chi )\) do not coincide.
- 8.
The Einstein-Friedmann equation (3.6) gives \(\ddot{a} < 0\) in this case.
- 9.
These two examples, together with de Sitter space for k = 0, are presented in Ref. [26]. However, contrary to what is stated in this reference, in both cases the event horizon is not constant: it is the apparent horizon which is constant.
- 10.
Cf. Table 1 of Ref. [39].
- 11.
The coordinates \(\left (t,R,\theta,\varphi \right )\) are called “Painlevé-de Sitter coordinates” [72].
- 12.
In general, the entropy density of a perfect fluid is \(s = \frac{P+\rho } {T}\) [54].
- 13.
References
Akbar, M., Cai, R.-G.: Friedmann equations of FRW universe in scalar-tensor gravity, f(R) gravity and first law of thermodynamics. Phys. Lett. B 635, 7 (2006)
Akbar, M., Cai, R.-G.: Thermodynamic behavior of the Friedmann equation at the apparent horizon of the FRW universe. Phys. Rev. D 75, 084003 (2007)
Angheben, M., Nadalini, M., Vanzo, L., Zerbini, S.: Hawking radiation as tunneling for extremal and rotating black holes. J. High Energy Phys. 05, 014 (2005)
Ashtekar, A., Krishnan, B.: Isolated and dynamical horizons and their applications. Living Rev. Relat. 7, 10 (2004)
Bak, D., Rey, S.-J.: Cosmic holography. Class. Quantum Grav. 17, L83 (2000)
Balasubramanian, V., de Boer, J., Minic, D.: Mass, entropy and holography in asymptotically de Sitter spaces. Phys. Rev. D 65, 123508 (2002)
Banks, T., Fischler, W.: An upper bound on the number of e-foldings. Preprint arXiv:astro-ph/0307459
Ben-Dov, I.: Outer trapped surfaces in Vaidya spacetimes. Phys. Rev. D 75, 064007 (2007)
Bengtsson, I., Senovilla, J.M.M.: Region with trapped surfaces in spherical symmetry, its core, and their boundaries. Phys. Rev. D 83, 044012 (2011)
Bhattacharya, S., Lahiri, A.: On the existence of cosmological event horizons. Class. Quantum Grav. 27, 165015 (2010)
Birrell, N.D., Davies, P.C.W.: Quantum Fields in Curved Space. Cambridge University Press, Cambridge (1982)
Booth, I., Brits, L., Gonzalez, J.A., Van den Broeck, V.: Black hole boundaries. Class. Quantum Grav. 23, 413 (2006)
Bousso, R.: A covariant entropy conjecture. J. High Energy Phys. 07, 004 (1999)
Bousso, R.: Positive vacuum energy and the N bound. J. High Energy Phys. 11, 038 (2000)
Bousso, R.: Cosmology and the S-matrix. Phys. Rev. D 71, 064024 (2005)
Bousso, R.: Adventures in de Sitter space. Preprint arXiv:hep-th/0205177
Brustein, R., Veneziano, G.: Causal entropy bound for a spacelike region. Phys. Rev. Lett. 84, 5695 (2000)
Cai, R.-G.: Holography, the cosmological constant and the upper limit of the number of e-foldings. J. Cosmol. Astropart. Phys. 02, 007 (2004)
Cai, R.-G., Kim, S.P.: First law of thermodynamics and Friedmann equations of Friedmann-Robertson-Walker universe. J. High Energy Phys. 0502, 050 (2005)
Cai, R.-G., Cao, L.-M., Hu, Y.-P.: Hawking radiation of an apparent horizon in a FRW universe. Class. Quantum Grav. 26, 155018 (2009)
Chakraborty, S., Mazumder, N., Biswas, R.: Cosmological evolution across phantom crossing and the nature of the horizon. Astrophys. Sp. Sci. 334, 183 (2011)
Collins, W.: Mechanics of apparent horizons. Phys. Rev. D 45, 495 (1992)
Danielsson, U.H.: Transplanckian energy production and slow roll inflatioon. Phys. Rev. D 71, 023516 (2005)
Das, A., Chattopadhyay, S., Debnath, U.: Validity of generalized second law of thermodynamics in the logamediate and intermediate scenarios of the universe. Found. Phys. 42, 266 (2011)
Davies, P.C.W.: Mining the universe. Phys. Rev. D 30, 737 (1984)
Davies, P.C.W.: Cosmological horizons and entropy. Class. Quantum Grav. 5, 1349 (1988)
Davies, P.C.W., Ford, L.H., Page, D.N.: Gravitational entropy: beyond the black hole. Phys. Rev. D 34, 1700 (1986)
Davis, T.M., Davies, P.C.W.: How far can the generalized second law be generalized? Found. Phys. 32, 1877 (2002)
Davis, T.M., Davies, P.C.W., Lineweaver, C.H.: Black hole versus cosmological horizon entropy. Class. Quantum Grav. 20, 2753 (2003)
Di Criscienzo, R., Hayward, S.A., Nadalini, M., Vanzo, L., Zerbini, S.: On the Hawking radiation as tunneling for a class of dynamical black holes. Class. Quantum Grav. 27, 015006 (2010)
d’Inverno, R.: Introducing Einstein’s Relativity. Oxford University Press, Oxford (2002)
Doran, C.: A new form of the Kerr solution. Phys. Rev. D 61, 06750 (2000)
Easther, R., Lowe, D.A.: Holography, cosmology, and the second law of thermodynamics. Phys. Rev. Lett. 82, 4967 (1999)
Eling, C., Guedens, R., Jacobson, T.: Nonequilibrium thermodynamics of spacetime. Phys. Rev. Lett. 96, 121301 (2006)
Faraoni, V.: Apparent and trapping cosmological horizons. Phys. Rev. D 84, 024003 (2011)
Faraoni, V., Nielsen, A.B.: Quasi-local horizons, horizon-entropy, and conformal field redefinitions. Class. Quantum Grav. 28, 175008 (2011)
Fischler, W., Susskind, L.: Holography and cosmology. Preprint arXiv:hep-th/9806039
Fischler, W., Loewy, A., Paban, S.: The entropy of the microwave background and the acceleration of the universe. J. High Energy Phys. 09, 024 (2003)
Frolov, A., Kofman, L.: Inflation and de Sitter thermodynamics. J. Cosmol. Astropart. Phys. 0305, 009 (2003)
Ghersi, J.T.G., Geshnizjani, G., Piazza, F., Shandera, S.: Eternal inflation and a thermodynamic treatment of Einstein’s equations. J. Cosmol. Astropart. Phys. 1106, 005 (2011)
Gibbons, G.W., Hawking, S.W.: Cosmological event horizon, thermodynamics, and particle creation. Phys. Rev. D 15, 2738 (1977)
Guth, A.H.: The inflationary universe: a possible solution to the horizon and flatness problems. Phys. Rev. D 23, 347 (1981)
Hawking, S.W.: Information preservation and weather forecasting for black holes. Preprint arXiv:1401.5761
Hawking, S.W., Ellis, G.F.R.: The Large Scale Structure of Space-Time. Cambridge University Press, Cambridge (1973)
Hayward, S.A.: Gravitational energy in spherical symmetry. Phys. Rev. D 53, 1938 (1996)
Hayward, S.A.: Unified first law of black-hole dynamics and relativistic thermodynamics. Class. Quantum Grav. 15, 3147 (1998)
Hayward, S.A., Mukohyama, S., Ashworth, M.C.: Dynamic black holes and entropy. Phys. Lett. A 256, 347 (1999)
Ibison, M.: On the conformal forms of the Robertson-Walker metric. J. Math. Phys. 48, 122501 (2007)
Infeld, L., Schild, A.: A new approach to kinematic cosmology. Phys. Rev. 68, 250 (1945)
Jacobson, T.: Thermodynamics of spacetime: the Einstein equation of state. Phys. Rev. Lett. 75, 1260 (1995)
Jang, K.-X., Feng, T., Peng, D.-T.: Hawking radiation of apparent horizon in a FRW universe as tunneling beyond semiclassical approximation. Int. J. Theor. Phys. 48, 2112 (2009)
Kaloper, N., Linde, A.D.: Cosmology versus holography. Phys. Rev. D 60, 103509 (1999)
Kaloper, N., Kleban, M., Sorbo, L.: Observational implications of cosmological event horizons. Phys. Lett. B 600, 7 (2004)
Kolb, E.W., Turner, M.S.: The Early Universe. Addison-Wesley, Reading (1990)
Kraus, P., Wilczek, F.: Some applications of a simple stationary line element for the Schwarzschild geometry. Mod. Phys. Lett. A 9, 3713 (1995)
Li, R., Ren, J.-R., Shi, D.-F.: Fermions tunneling from apparent horizon of FRW universe. Phys. Lett. B 670, 446 (2009)
Liddle, A.R., Lyth, D.H.: Cosmological Inflation and Large Scale Structure. Cambridge University Press, Cambridge (2000)
Lowe, D.A., Marolf, D.: Holography and eternal inflation. Phys. Rev. D 70, 026001 (2004)
Martel, K., Poisson, E.: Regular coordinate systems for Schwarzschild and other spherical spacetimes. Am. J. Phys. 69, 476 (2001)
Mazumder, N., Biswas, R., Chakraborty, S.: Interacting three fluid system and thermodynamics of the universe bounded by the event horizon. Gen. Rel. Gravit. 43, 1337 (2011)
McVittie, G.C.: The mass-particle in an expanding universe. Mon. Not. R. Astr. Soc. 93, 325 (1933)
Medved, A.J.M.: Radiation via tunneling from a de Sitter cosmological horizon. Phys. Rev. D 66, 124009 (2002)
Medved, A.J.M.: A brief editorial on de Sitter radiation via tunneling. Preprint arXiv:0802.3796
Mosheni Sadjadi, H.: Generalized second law in a phantom-dominated universe. Phys. Rev. D 73, 0635325 (2006)
Mottola, E.: Thermodynamic instability of de Sitter space. Phys. Rev. D 33, 1616 (1986)
Mukhanov, V.: Physical Foundations of Cosmology. Cambridge University Press, Cambridge (2005)
Nielsen, A.B., Yeom, D.-H.: Black holes without boundaries. Int. J. Mod. Phys. A 24, 5261 (2009)
Nielsen, A.B., Visser, M.: Production and decay of evolving horizons. Class. Quantum Grav. 23, 4637 (2006)
Nolan, B.C.: Sources for McVittie’s mass particle in an expanding universe. Phys. Rev. D 58, 064006 (1998)
Nolan, B.C.: A Point mass in an isotropic universe. 2. Global properties. Class. Quantum Grav. 16, 1227 (1999)
Nolan, B.C.: A Point mass in an isotropic universe 3. The region R ≤ 2m. Class. Quantum Grav. 16, 3183 (1999)
Parikh, M.K.: New coordinates for de Sitter space and de Sitter radiation. Phys. Lett. B 546, 189 (2002)
Parikh, M.K., Wilczek, F.: Hawking radiation as tunneling. Phys. Rev. Lett. 85, 5042 (2000)
Piao, Y.-S.: Entropy of the microwave background radiation in the observable universe. Phys. Rev. D 74, 47301 (2006)
Rindler, W.: Visual horizons in world-models. Mon. Not. R. Astr. Soc. 116, 663 (1956) (reprinted in Gen. Rel. Gravit. 34, 133 (2002))
Sekiwa, Y.: Decay of the cosmological constant by Hawking radiation as quantum tunneling. Preprint arXiv:0802.3266
Senovilla, J.M.M.: Singularity theorems and their consequences. Gen. Rel. Grav. 30, 701 (1998)
Spradlin, M.A., Strominger, A., Volovich, A.: Les Houches lectures on de Sitter space. In Les Houches 2001, Gravity, Gauge Theories and Strings, Proceedings of the Les Houches Summer School 76, Les Houches, pp. 423–453 (2001). (Preprint arXiv:hep-th/011007)
Spradlin, M.A., Volovich, A.: Vacuum states and the S matrix in dS/CFT. Phys. Rev. D 65, 104037 (2002)
Stephani, H.: General Relativity. Cambridge University Press, Cambridge (1982)
Veneziano, G.: Pre-bangian origin of our entropy and time arrow. Phys. Lett. B 454, 22 (1999)
Verlinde, E.: On the holographic principle in a radiation-dominated universe. Preprint arXiv:hep-th/0008140
Visser, M.: Essential and inessential features of Hawking radiation. Int. J. Mod. Phys. D 12, 649 (2003)
Wang, B., Abdalla, E.: Plausible upper limit on the number of e-foldings. Phys. Rev. D 69, 104014 (2004)
Wang, B., Gong, Y., Abdalla, E.: Thermodynamics of an accelerated expanding universe. Phys. Rev. D 74, 083520 (2006)
Zhu, T., Ren, J.-R.: Corrections to Hawking-like radiation for a Friedmann-Robertson-Walker universe. Eur. Phys. J. C 62, 413 (2009)
Author information
Authors and Affiliations
Rights and permissions
Copyright information
© 2015 Springer International Publishing Switzerland
About this chapter
Cite this chapter
Faraoni, V. (2015). Cosmological Horizons. In: Cosmological and Black Hole Apparent Horizons. Lecture Notes in Physics, vol 907. Springer, Cham. https://doi.org/10.1007/978-3-319-19240-6_3
Download citation
DOI: https://doi.org/10.1007/978-3-319-19240-6_3
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-19239-0
Online ISBN: 978-3-319-19240-6
eBook Packages: Physics and AstronomyPhysics and Astronomy (R0)