Accretion Flow onto Ellis–Bronnikov Wormhole

Abstract

Study of accretion onto wormholes is rather rare compared to that onto black holes. In this paper, we consider accretion flow of cosmological dark energy modeled by barotropic fluid onto the celebrated Ellis–Bronnikov wormhole (EBWH) built by Einstein minimally coupled scalar field ϕ, violating the null energy condition. The accreting fluid is assumed to be phantom, quintessence, dust and stiff matter. We begin by first pointing out a mathematical novelty showing how the EBWH can lead to the Schwarzschild black hole under a complex Wick rotation. Then, we analyze the profiles of fluid radial velocity, density and the rate of mass variation of the EBWH due to accretion and compare the profiles with those of the Schwarzschild black hole. We also analyze accretion to the massless EBWH that has zero ADM mass but has what we call nonzero Wheelerian mass (“mass without mass”), composed of the non-trivial scalar field, that shows gravitational effects. Our conclusion is that the mass of SBH due to phantom accretion decreases consistently with known results, while, in contrast, the mass of EBWH increases. Exactly an opposite behavior emerges for non-phantom accretion to these two objects. Accretion to massless EBWH (i.e., to nonzero Wheelerian mass) shares the same patterns as those of the massive EBWH; hence there is no way to distinguish massive and massless cases by means of accretion flow. The contrasting mass variations due to phantom accretion could be a reflection of the distinct topology of the central objects.

Ellis–Bronnikov Wormholes in Asymptotically Safe Gravity

“…Now, we will analyze the radial energy conditions of the Ellis-Bronnikov wormhole. Such conditions are verified from the substitution of Equation ( 14) into Equations ( 11) and (12). We get:…”

“…Wormholes and their traversability are an object of intense discussion in the communities which study general relativity and it's extensions. By means of Einstein's theory, one shows [1][2][3][4] that the wormhole is traversable only with the presence of exotic matter, including Casimir energy [5][6][7][8][9], even being capable of mimicing the behavior of black holes [10][11][12]. Classically modified gravity theories involving wormholes (e.g., Einstein-Gauss-Bonett gravity [13], Lovelock gravity [14], Einstein-Born-Infeld gravity [15], and others [16][17][18][19]), as well as some quantum corrected ones [20], are also often discussed in the literature.…”

Einstein and Møller Energy-Momentum Distributions for the Static Regular Simpson–Visser Space-Time

“…Wheeler for his geon, see e.g., [51]) responsible for the gravitational reaction of this wormhole. Indeed, despite the zero ADM mass, these massless wormholes can be sourced by other (rather exotic) fields, such as a ghost scalar field (having negative energy density) or a dilaton field, that can attribute a non-zero mass to the wormhole and thus equip it with a strong lensing behavior (see, e.g., [52,53]). The regular black holes and traversable wormholes are distinct and interesting scenarios, and have been the subject of various studies.…”

Ellis-Bronnikov Wormholes in Asymptotically Safe Gravity

“…Wormholes and their traversability are an object of intense discussion in the communities which study General Relativity and its extensions. By means of Einstein's theory, one shows [1][2][3][4] that the wormhole is traversable only with the presence of exotic matter, including Casimir energy [8][9][10][11][12], being even capable to mimic the behavior of black holes [5][6][7]. Classically modified gravity theories involving wormholes (e.g.…”