Matches in SemOpenAlex for { <https://semopenalex.org/work/W2069721863> ?p ?o ?g. }
Showing items 1 to 97 of
97
with 100 items per page.
- W2069721863 endingPage "586" @default.
- W2069721863 startingPage "559" @default.
- W2069721863 abstract "Causal solutions of the Gödel type, for which the line element is ds 2 = dt 2 - 2b e mx dtdv - c e 2mx dv 2 - dx 2 - dz 2 with c = 0, are known to exist for gravitational theories containing a cosmological constant Λ and quadratic higher-derivative terms defined by the Lagrangian L = -(1/2)κ -2 (R + 2Λ) + A 1 R 2 + A 2 R ij R ij . Here, we show that acausal solutions, for which c < 0, containing closed time-like lines, can be constructed only if A 2 = 0. Extension of this analysis to the heterotic superstring theory, including a generic massless scalar field ϕ plus quadratic and quartic gravitational terms [Formula: see text] and [Formula: see text], again yields a causal solution with c = 0, and also Λ = 0, as required for anomaly freedom, while solutions with c < 0 are ruled out. More general rotational space–times appear to be intractable analytically, and therefore it remains a matter of conjecture that the heterotic superstring admits only classical Lorentzian solutions which respect causality. For the energy density ρ(ϕ) of the scalar field is positive semi-definite only when g 00 ≥ 0, which is equivalent to the causality condition g 11 ≤ 0 or c ≥ 0 in a Lorentzian space–time for which det g ij < 0; while ρ(ϕ) is unbounded from below in the presence of closed time-like lines, when g 11 > 0, implying instability of ϕ, which will react back on the metric until it becomes causal." @default.
- W2069721863 created "2016-06-24" @default.
- W2069721863 creator A5000864896 @default.
- W2069721863 date "2009-04-01" @default.
- W2069721863 modified "2023-09-27" @default.
- W2069721863 title "DOES THE HETEROTIC SUPERSTRING THEORY CONTAIN CLOSED TIME-LIKE LINES?" @default.
- W2069721863 cites W1612099944 @default.
- W2069721863 cites W1953478438 @default.
- W2069721863 cites W1969454298 @default.
- W2069721863 cites W1980979713 @default.
- W2069721863 cites W1984308457 @default.
- W2069721863 cites W1987786885 @default.
- W2069721863 cites W1992731726 @default.
- W2069721863 cites W1995131899 @default.
- W2069721863 cites W2000226231 @default.
- W2069721863 cites W2005483142 @default.
- W2069721863 cites W2019232242 @default.
- W2069721863 cites W2026408654 @default.
- W2069721863 cites W2027332450 @default.
- W2069721863 cites W2035152063 @default.
- W2069721863 cites W2036554114 @default.
- W2069721863 cites W2042178891 @default.
- W2069721863 cites W2051284488 @default.
- W2069721863 cites W2058986300 @default.
- W2069721863 cites W2059748433 @default.
- W2069721863 cites W2063678443 @default.
- W2069721863 cites W2068838164 @default.
- W2069721863 cites W2069452530 @default.
- W2069721863 cites W2076133097 @default.
- W2069721863 cites W2077734079 @default.
- W2069721863 cites W2078629924 @default.
- W2069721863 cites W2081412487 @default.
- W2069721863 cites W2082571528 @default.
- W2069721863 cites W2093709217 @default.
- W2069721863 cites W2104656181 @default.
- W2069721863 cites W2110764851 @default.
- W2069721863 cites W2157606627 @default.
- W2069721863 cites W2316010860 @default.
- W2069721863 cites W2324068500 @default.
- W2069721863 cites W2952332536 @default.
- W2069721863 cites W3104628550 @default.
- W2069721863 cites W4229612929 @default.
- W2069721863 cites W4229824384 @default.
- W2069721863 cites W4236570223 @default.
- W2069721863 cites W4249391714 @default.
- W2069721863 doi "https://doi.org/10.1142/s0218271809014637" @default.
- W2069721863 hasPublicationYear "2009" @default.
- W2069721863 type Work @default.
- W2069721863 sameAs 2069721863 @default.
- W2069721863 citedByCount "1" @default.
- W2069721863 crossrefType "journal-article" @default.
- W2069721863 hasAuthorship W2069721863A5000864896 @default.
- W2069721863 hasConcept C110521144 @default.
- W2069721863 hasConcept C116674579 @default.
- W2069721863 hasConcept C121332964 @default.
- W2069721863 hasConcept C130187892 @default.
- W2069721863 hasConcept C20288 @default.
- W2069721863 hasConcept C2524010 @default.
- W2069721863 hasConcept C33923547 @default.
- W2069721863 hasConcept C37914503 @default.
- W2069721863 hasConcept C54937798 @default.
- W2069721863 hasConcept C57691317 @default.
- W2069721863 hasConcept C62520636 @default.
- W2069721863 hasConcept C96732373 @default.
- W2069721863 hasConceptScore W2069721863C110521144 @default.
- W2069721863 hasConceptScore W2069721863C116674579 @default.
- W2069721863 hasConceptScore W2069721863C121332964 @default.
- W2069721863 hasConceptScore W2069721863C130187892 @default.
- W2069721863 hasConceptScore W2069721863C20288 @default.
- W2069721863 hasConceptScore W2069721863C2524010 @default.
- W2069721863 hasConceptScore W2069721863C33923547 @default.
- W2069721863 hasConceptScore W2069721863C37914503 @default.
- W2069721863 hasConceptScore W2069721863C54937798 @default.
- W2069721863 hasConceptScore W2069721863C57691317 @default.
- W2069721863 hasConceptScore W2069721863C62520636 @default.
- W2069721863 hasConceptScore W2069721863C96732373 @default.
- W2069721863 hasIssue "04" @default.
- W2069721863 hasLocation W20697218631 @default.
- W2069721863 hasOpenAccess W2069721863 @default.
- W2069721863 hasPrimaryLocation W20697218631 @default.
- W2069721863 hasRelatedWork W1569316233 @default.
- W2069721863 hasRelatedWork W2046135611 @default.
- W2069721863 hasRelatedWork W2069721863 @default.
- W2069721863 hasRelatedWork W2079966906 @default.
- W2069721863 hasRelatedWork W2221847392 @default.
- W2069721863 hasRelatedWork W2523714029 @default.
- W2069721863 hasRelatedWork W2871956755 @default.
- W2069721863 hasRelatedWork W2884702561 @default.
- W2069721863 hasRelatedWork W2936002436 @default.
- W2069721863 hasRelatedWork W2995401851 @default.
- W2069721863 hasVolume "18" @default.
- W2069721863 isParatext "false" @default.
- W2069721863 isRetracted "false" @default.
- W2069721863 magId "2069721863" @default.
- W2069721863 workType "article" @default.