Cosmological event horizons, thermodynamics, and particle creation

@article{citeulike:1320394, abstract = {It is shown that the close connection between event horizons and thermodynamics which has been found in the case of black holes can be extended to cosmological models with a repulsive cosmological constant. An observer in these models will have an event horizon whose area can be interpreted as the entropy or lack of information of the observer about the regions which he cannot see. Associated with the event horizon is a surface gravity κ which enters a classical "first law of event horizons" in a manner similar to that in which temperature occurs in the first law of thermodynamics. It is shown that this similarity is more than an analogy: An observer with a particle detector will indeed observe a background of thermal radiation coming apparently from the cosmological event horizon. If the observer absorbs some of this radiation; he will gain energy and entropy at the expense of the region beyond his ken and the event horizon will shrink. The derivation of these results involves abandoning the idea that particles should be defined in an observer-independent manner. They also suggest that one has to use something like the Everett-Wheeler interpretation of quantum mechanics because the back reaction and hence the spacetime metric itself appear to be observer-dependent; if one assumes; as seems reasonable; that the detection of a particle is accompanied by a change in the gravitational field.}, author = {Gibbons, G. W. and Hawking, S. W. }, citeulike-article-id = {1320394}, doi = {http://dx.doi.org/10.1103/PhysRevD.15.2738}, journal = {Physical Review D}, keywords = {cosmology}, month = {May}, number = {10}, pages = {2738+}, posted-at = {2007-05-23 06:45:33}, priority = {2}, publisher = {American Physical Society}, title = {Cosmological event horizons, thermodynamics, and particle creation}, url = {http://dx.doi.org/10.1103/PhysRevD.15.2738}, volume = {15}, year = {1977} }

TY - JOUR ID - citeulike:1320394 L3 - citeulike-article-id:1320394 N2 - It is shown that the close connection between event horizons and thermodynamics which has been found in the case of black holes can be extended to cosmological models with a repulsive cosmological constant. An observer in these models will have an event horizon whose area can be interpreted as the entropy or lack of information of the observer about the regions which he cannot see. Associated with the event horizon is a surface gravity κ which enters a classical "first law of event horizons" in a manner similar to that in which temperature occurs in the first law of thermodynamics. It is shown that this similarity is more than an analogy: An observer with a particle detector will indeed observe a background of thermal radiation coming apparently from the cosmological event horizon. If the observer absorbs some of this radiation; he will gain energy and entropy at the expense of the region beyond his ken and the event horizon will shrink. The derivation of these results involves abandoning the idea that particles should be defined in an observer-independent manner. They also suggest that one has to use something like the Everett-Wheeler interpretation of quantum mechanics because the back reaction and hence the spacetime metric itself appear to be observer-dependent; if one assumes; as seems reasonable; that the detection of a particle is accompanied by a change in the gravitational field. IS - 10 JF - Physical Review D TI - Cosmological event horizons, thermodynamics, and particle creation PB - American Physical Society VL - 15 SP - 2738 KW - cosmology AU - Gibbons, GW AU - Hawking, SW PY - 1977/05/15/ UR - http://dx.doi.org/10.1103/PhysRevD.15.2738 ER -