In search for natural wormholes

Physical Review D, 1998

The extragalactic microlensing scenario for natural wormholes is examined. It is shown that the main features of wormhole lensing events upon the light of distant Active Galactic Nuclei (AGNs) are similar to some types of already observed Gamma Ray Bursts (GRBs). Using recent satellite data on GRBs, an upper limit to the negative mass density -- ${\cal O} (10^{-36})$ g cm$^{-3}$ -- under the form of wormhole-like objects is presented.

2010

We consider observational properties of gamma-ray bursts (GRB) transmitted by hypothetical wormholes (WH). Such burst would be observable as repeating source, analogous to Soft Gamma-Repeaters (SGR). We show that the known sources of SGR cannot be WH candidates. We also discuss observational properties of GRB which might be a signature of WH.

Physical Review D, 1995

Visser has suggested traversable 3-dimensional wormholes that could plausibly form naturally during Big Bang inflation. A wormhole mouth embedded in high mass density might accrete mass, giving the other mouth a net *negative* mass of unusual gravitational properties. The lensing of such a gravitationally negative anomalous compact halo object (GNACHO) will enhance background stars with a time profile that is observable and qualitatively different from that recently observed for massive compact halo objects (MACHOs) of positive mass. We recommend that MACHO search data be analyzed for GNACHOs.

arXiv (Cornell University), 2023

1993

In this letter we propose a physical explanation for recently reported correlations between pairs of close and antipodal gamma-ray bursts from publicly available BATSE catalogue. Our model is based on the cosmological scenario in which bursters are located at cosmological distances of order of 0.5--2~Gpc. Observed distribution of gamma-ray bursts strongly suports this assumption. If so gamma-ray bursts may provide a very good probe for investigating the topological structure of the Universe. We notice that correlation between antipodal events may in fact indicate that we live in the so called Ellis' small universe which has Friedman-Roberston-Walker metric structure and nontrivial topology.

Modern Physics Letters A, 1998

In this letter, we assume that negative mass objects can exist in the extragalactic space and analyze the consequences of their microlensing on light from distant active galactic nuclei. We find that such events have very similar features to some observed gamma ray bursts and use recent satellite data to set an upper bound to the amount of negative mass in the universe.

Physical Review D, 2001

We provide an in depth study of the theoretical peculiarities that arise in effective negative mass lensing, both for the case of a point mass lens and source, and for extended source situations. We describe novel observational signatures arising in the case of a source lensed by a negative mass. We show that a negative mass lens produces total or partial eclipse of the source in the umbra region and also show that the usual Shapiro time delay is replaced with an equivalent time gain. We describe these features both theoretically, as well as through numerical simulations. We provide negative mass microlensing simulations for various intensity profiles and discuss the differences between them. The light curves for microlensing events are presented and contrasted with those due to lensing produced by normal matter. Presence or absence of these features in the observed microlensing events can shed light on the existence of natural wormholes in the Universe.