June 28, 2019
From 10:30 until 12:00

Frédéric Marin Observatoire astronomique de Strasbourg Worldships are hypothetical, large,...

Home   >   Research   >   Seminars and meetings   >   Internal seminars : Relativistic charge solitons caused due to Nonlinear-Landau damping : A candidate to explain coherent radio emission from pulsars

Relativistic charge solitons caused due to Nonlinear-Landau damping : A candidate to explain coherent radio emission from pulsars

May 24, 2019
From 10:30 until 12:00

Dipanjan Mitra

National Centre for Radio Astrophysics, Tata Institute of Fundamental Research


Collective plasma emissions in astrophysics are referred to as coherent emission. Radio emission from pulsars are coherent in nature,and observations strongly suggest that: (a) the coherent emission is excited by acceleration of ``charge bunches'' in a 1D relativisticallymoving pair plasma, and (b) the radio emission occurs at a frequencylower than the local plasma frequency. Theoretically, it is challenging to form a stable charge bunch that follow the above observational constraints, and even after fifty years of pulsar discovery the mechanism of how collective plasma process excites the coherent radio emission remains an unresolved problem.

In this talk we will propose a potential resolution for the formation of charge bunches, based on a kinetic theory of linear and non-linear growth of electrostatic Langmuir waves in the relativistic pair plasma.  In the non-linear regime, we will demonstrate the existence of relativistic charge solitons (the “charge bunches”) as solutions of the non-linear Schrodinger equation (NLSE). The formalism includes the crucial effect of non-linear Landau damping, which is inherent in the derivation of the NLSE. We will also demonstrate a remarkable finding, i.e. the emergence of these intense soliton-like pulses from an initial disordered state of Langmuir waves.


Search & Find
Apr 25 2018

Astronomers worldwide are eagerly awaiting for April 25 2018. This is the date the European Space...

May 15 2019

Large spiral galaxies, like our nearest neighbour the Andromeda Galaxy, leave almost no gas or dust...

Apr 23 2019

A team of researchers from the Strasbourg Astronomical Observatory, Bologna Observatory and the...

Mar 28 2019

Rodrigo Ibata, directeur de recherche CNRS à l'Observatoire astronomique de Strasbourg...

Feb 28 2019

We all know bubbles from soapy baths or sodas. These bubbles of everyday experience on Earth are...