{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,13]],"date-time":"2026-02-13T06:21:27Z","timestamp":1770963687045,"version":"3.50.1"},"reference-count":40,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2026,2,6]],"date-time":"2026-02-06T00:00:00Z","timestamp":1770336000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Information"],"abstract":"<jats:p>We develop an informational extension of spacetime thermodynamics in which local entropy production is coupled to spacetime curvature within an effective covariant framework. Spacetime is modeled as a continuum limit of finite-capacity information registers, giving rise to a coarse-grained entropy field whose gradients define an informational flux. Within a nonminimally coupled scalar\u2013tensor formulation, the resulting field equations imply that the local divergence of this flux is sourced by the Ricci scalar, establishing a direct relation between curvature and entropy production. The corresponding integral form links cumulative entropy generation to the integrated spacetime curvature over a causal region. In stationary limits, the framework reproduces the Bekenstein\u2013Hawking entropy of horizons, while in homogeneous expanding cosmologies it yields monotonic entropy growth consistent with the observed arrow of time. The construction remains compatible with unitarity at the microscopic level and with holographic entropy bounds in the stationary limit. Numerical solutions in flat FLRW backgrounds are used as consistency checks of the coupled evolution equations and confirm the expected curvature\u2013entropy behavior across cosmological epochs. Overall, the results provide a thermodynamically consistent interpretation of curvature as a geometric source of irreversible information flow, without modifying the underlying gravitational field equations.<\/jats:p>","DOI":"10.3390\/info17020169","type":"journal-article","created":{"date-parts":[[2026,2,6]],"date-time":"2026-02-06T16:32:59Z","timestamp":1770395579000},"page":"169","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Entropy, Information, and the Curvature of Spacetime in the Informational Second Law"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2562-1618","authenticated-orcid":false,"given":"Florian","family":"Neukart","sequence":"first","affiliation":[{"name":"Leiden Institute of Advanced Computer Science, Leiden University, Gorlaeus Gebouw-BE-Vleugel, Einsteinweg 55, 2333 Leiden, The Netherlands"},{"name":"Terra Quantum AG, Kornhausstrasse 25, 9000 St. Gallen, Switzerland"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-0228-1296","authenticated-orcid":false,"given":"Eike","family":"Marx","sequence":"additional","affiliation":[{"name":"Terra Quantum AG, Kornhausstrasse 25, 9000 St. Gallen, Switzerland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0977-3515","authenticated-orcid":false,"given":"Valerii","family":"Vinokur","sequence":"additional","affiliation":[{"name":"Terra Quantum AG, Kornhausstrasse 25, 9000 St. Gallen, Switzerland"}]}],"member":"1968","published-online":{"date-parts":[[2026,2,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"500","DOI":"10.1002\/andp.18501550403","article-title":"On the Motive Power of Heat, and on the Laws which can be deduced from it for the Theory of Heat","volume":"155","author":"Clausius","year":"1850","journal-title":"Ann. 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