640 research outputs found
Quantum Gravity signatures in the Unruh effect
We study quantum gravity signatures emerging from phenomenologically
motivated multiscale models, spectral actions, and Causal Set Theory within the
detector approach to the Unruh effect. We show that while the Unruh temperature
is unaffected, Lorentz-invariant corrections to the two-point function leave a
characteristic fingerprint in the induced emission rate of the accelerated
detector. Generically, quantum gravity models exhibiting dynamical dimensional
reduction exhibit a suppression of the Unruh rate at high energy while the rate
is enhanced in Kaluza-Klein theories with compact extra dimensions. We quantify
this behavior by introducing the "Unruh dimension" as the effective spacetime
dimension seen by the Unruh effect and show that it is related, though not
identical, to the spectral dimension used to characterize spacetime in quantum
gravity. We comment on the physical origins of these effects and their
relevance for black hole evaporation.Comment: 38 pages, 7 figures; v3: section 2 rewritten, references adde
A proof of the 3/5-conjecture in the domination game
The domination game is an optimization game played by two players, Dominator
and Staller, who alternately select vertices in a graph . A vertex is said
to be dominated if it has been selected or is adjacent to a selected vertex.
Each selected vertex must strictly increase the number of dominated vertices at
the time of its selection, and the game ends once every vertex in is
dominated. Dominator aims to keep the game as short as possible, while Staller
tries to achieve the opposite. In this article, we prove that for any graph
on vertices, Dominator has a strategy to end the game in at most
moves, which was conjectured by Kinnersley, West and Zamani.Comment: 30 pages, 6 figure
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