Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · gr-qc/9809081

Energy-momentum tensor of quasiparticles in the effective gravity in superfluids

G. E. Volovik
View original source ↗Read source document ↗Export metadata ↓

Abstract

The problem of the energy-momentum conservation for matter in the gravitational field is discussed on the example of the effective gravity, which arises in superfluids. The "gravitational" field experienced by the relativistic-like massless quasiparticles which form the "matter" (phonons in superfluid 4He and low-energy fermions in superfluid 3He-A), is induced by the flow of the superfluid "vacuum". It appears that the energy-momentum conservation law for quasiparticles, has the covariant form T^μ_{ν;μ}=0. "Pseudotensor" of the energy-momentum for the "gravitational field" (superfluid condensate) appears to depend on "matter". In the presence of the stationary "gravitational" (superfluid) field the real thermodynamic temperature T is constant in the true dissipationless equilibrium state with no entropy production, while the "relativistic" temperature T/\sqrt{g_{00}} is space dependent in agreement with Tolman's law. In the presence of the event horizon the true dissipationless equilibrium state does not exist. The quasiequilibrium dissipative motion across the horizon is considered. The inflationary stage of the expansion of the Universe can be modelled using the expanding Bose-condendsate.

Explore related subjects

gr-qc

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

G. E. Volovik. 1998-10-25. Energy-momentum tensor of quasiparticles in the effective gravity in superfluids. https://arxiv.org/abs/gr-qc/9809081

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

An upper bound on the minimum orbital period of black holes

Previous research has focused on establishing lower bounds on the minimum orbital period of black holes. In this work, we explore the complementary question of whether an upper bound exists for the minimum orbital period of black holes. We investigate the minimum orbital periods of three types of black holes: Schwarzschild, Reissner-Nordström and Kerr-Newman black holes. We find that the minimum orbital period of these black holes is bounded by an upper limit $T_{min} \leqslant 6\sqrt{3}πM$, where $M$ is the black hole mass. Our results suggest that this upper bound on the minimum orbital period may be a general property in black hole spacetimes.

gr-qc↗
arXiv2026

Bounds on the minimum orbital period in the background of 5-dimensional charged black holes

In this paper, we study the upper and lower bounds on the minimum orbital period of 5-dimensional charged black holes. Our results indicate that the upper bound of the minimum orbital period corresponds to non-charged black holes, while the lower bound is achieved in the case of maximally charged black holes. We further establish precise analytical expressions for the upper and lower bounds of the minimum orbital period. Our findings provide valuable insights into 5-dimensional charged black holes and help constrain theoretical gravity models.

gr-qc↗
arXiv2026

Analysis of minimum orbital periods around d-dimensional charged black holes

This paper investigates the bounds on the minimum orbital period for test objects around d-dimensional charged black holes in asymptotically flat spacetimes. We derive the exact critical radius and the minimum orbital period. We then prove analytically that the minimum orbital period decreases strictly as the charge of the black hole increases. Thus, the upper limit is reached for an uncharged black hole, while the lower limit is attained for a maximally charged one, and the two bounds take the closed form $\frac{2π(d-2)}{d-3}[(d-2)M]^{\frac{1}{d-3}}\leqslant T_{min} \leqslant 2π\sqrt{\frac{d-1}{d-3}}\,[(d-1)M]^{\frac{1}{d-3}}$. Since the minimum period equals $2π$ times the shadow radius, the upper bound is equivalently a universal upper bound on the shadow radius. These results improve our understanding of dynamics around d-dimensional black holes and impose constraints on candidate gravity theories.

gr-qc↗