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SUMMARY:Non-Conserved Gravity: A Thermodynamic Origin of Cosmic Accelerati
 on
DTSTART;VALUE=DATE-TIME:20261030T071500Z
DTEND;VALUE=DATE-TIME:20261030T073000Z
DTSTAMP;VALUE=DATE-TIME:20261101T211157Z
UID:indico-contribution-6277@cern.ch
DESCRIPTION:Speakers: Seyed Hamidreza Fazlollahi (RUDN)\nWe present a new 
 gravitational framework in which the conventional conservation of the ener
 gy-momentum tensor is relaxed and replaced by a non-conservation law motiv
 ated by relativistic thermodynamics. In this approach\, the exchange of en
 ergy and momentum between matter and the gravitational sector is treated a
 s a fundamental physical effect rather than as an effective description of
  an unknown dark-energy component. The resulting field equations extend Ei
 nstein gravity while retaining the standard geometric description of space
 time and the usual conservation law as a limiting case.\n\nWe investigate 
 the cosmological consequences of this non-conserved gravitational dynamics
  in a homogeneous and isotropic universe. The modified continuity equation
  introduces an additional matter–spacetime exchange term\, which changes
  the evolution of the cosmic energy density and generates an effective con
 tribution to the expansion dynamics. Remarkably\, the resulting cosmologic
 al evolution can produce a transition from decelerated to accelerated expa
 nsion without introducing a fundamental cosmological constant or an exotic
  dark-energy fluid. For suitable parameters\, the background evolution app
 roaches the behavior of the standard $\\Lambda$CDM model while providing a
  different physical interpretation of the source of late-time acceleration
 .\n\nThe framework therefore offers a thermodynamically motivated alternat
 ive to the conventional dark-energy picture and provides a direct connecti
 on between gravitational dynamics\, energy exchange\, and cosmological evo
 lution. We discuss the corresponding expansion history and the prospects f
 or confronting the model with observational cosmology\, including distance
 -redshift measurements and the evolution of the Hubble parameter. The resu
 lts suggest that violations of energy-momentum conservation\, when consist
 ently incorporated into gravitational thermodynamics\, may provide a viabl
 e route toward understanding cosmic acceleration without requiring an inde
 pendent dark-energy sector.\n\nhttps://indico.particle.mephi.ru/event/626/
 contributions/6277/
LOCATION: Conference Hall 4
URL:https://indico.particle.mephi.ru/event/626/contributions/6277/
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