scholarly journals Stimulated emission–based model of fast radio bursts

2020 ◽  
Vol 494 (1) ◽  
pp. 876-884 ◽  
Author(s):  
Mustafa Doğan ◽  
Kazım Yavuz Ekşi

ABSTRACT Fast radio bursts (FRBs) are bright, short-duration radio transients with very high brightness temperatures implying highly coherent emission. We suggest that the FRBs are caused by the self-focusing of an electron beam interacting with an ambient plasma right beyond the light cylinder radius of a neutron star. The magnetic field at the light cylinder radius is relatively high that can accommodate both young Crab-like systems and old millisecond pulsars addressing the diverse environments of FRBs. At the first stage, the intense pulsed-beam passing through the background plasma causes instabilities such that the trapped particles in local Buneman-type cavitons saturate the local field. The beam is then radially self-focused due to the circular electric field developed by the two-stream instability that leads to Weibel instability in the transverse direction. Finally, the non-linear saturation of the Weibel instability results in the self-modulational formation of solitons due to plasmoid instability. The resonant solitary waves are the breather-type solitons hosting relativistic particles with self-excited oscillations. The analytical solutions obtained for non-linear dispersion and solitons suggest that, near the current sheets, the relativistic bunches are accelerated/amplified by klystron-like structures due to self-excited oscillations by the induced local electric field. Boosted coherent radio emission propagates through a narrow cone with strong focusing due to radial electric field and magnetic pinching. The non-linear evolution of solitons and the stimulated emission are associated with the Buneman instability and the possibility of the presence of nanosecond shots in FRBs are investigated.

2019 ◽  
Vol 61 (5) ◽  
pp. 054003 ◽  
Author(s):  
A Krämer-Flecken ◽  
X Han ◽  
T Windisch ◽  
J Cosfeld ◽  
P Drews ◽  
...  

Author(s):  
Celine (Ha-Young) Song

A common question asked about the web 2.0 by the offline population is:  "What do people do there?" The paper addresses this question with respect to Paul Ricoeur's narrative theory of the self. According to his essay Life in Quest of Narrative, a person drifts through time experiencing events happening to them, but none of it is actually lived when it is not "recounted" or "storied". In this light, "storytelling may be said to humanise time by transforming it from an impersonal passing of fragmented moments into a patter, a plot ,a mythos". Blogs and sites like Facebook represent the most recent development in the human attempt to weave this "mythos". A profile page and a tweet are first and foremost stories that appear to its critics "truncated or parodied" by design "to the point of being called micro-narratives or post-narratives", and to it s advocates"multi-plotted, multi-vocal and multi-media". The paper introduces notions of e-Self and e-Narrative, examines their dangers and benefits, and concludes that "the advent of cyber-culture should be seen not as a threat to storytelling but as a catalyst for new possibilities of interactive, non-linear narration".


2021 ◽  
Vol 28 (6) ◽  
pp. 062507
Author(s):  
I. Senichenkov ◽  
E. Kaveeva ◽  
V. Rozhansky ◽  
D. Coster

2012 ◽  
Vol 52 (7) ◽  
pp. 074013 ◽  
Author(s):  
T. Zhang ◽  
Y. Liang ◽  
Y. Sun ◽  
A. Krämer-Flecken ◽  
S. Soldatov ◽  
...  

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