The tides of moving objects

Add to your list(s) Download to your calendar using vCal

• Prof. Jorge Peñarrubia (University of Edinburgh)
• Monday 24 February 2020, 14:00-15:00
• MR14, Centre for Mathematical Sciences, Wilberforce Road, Cambridge.

If you have a question about this talk, please contact Chris Hamilton.

Gravitational systems surrounded by a large number of substructures experience fluctuations of the external tidal field that inject energy into their internal motions. In this talk I will show that “tidal heating” can be statistically modelled as a random walk in velocity space, and compute the Green’s propagators from the number density and velocity distribution of substructures with known mass & size functions. In addition, a Monte-Carlo Markov-chain technique will be introduced which mimics the effects of an fluctuating tidal field by sampling velocity ’kicks’ from a probability function. Tests against direct-force N-body models show that (i) the new technique is extremely CPU effective, and (ii) it provides an accurate description of the response of gravitationally-bound particles to repeated tidal fluctuations in both impulsive and adiabatic regimes. For illustration, I will present idealized models that follow the dynamical evolution of planetary discs in a clumpy environment. The results indicate that the presence of a stochastic tidal field necessarily leads to the formation, and subsequent “evaporation” of Oort-like clouds, as well as to a sizeable population of comets on retrograde orbits.

This talk is part of the DAMTP Astrophysics Seminars series.

This talk is included in these lists:

• All CMS events
• CMS Events
• Cambridge Astronomy Talks
• Cosmology, Astrophysics and General Relativity
• DAMTP Astrophysics Seminars
• DAMTP info aggregator
• Interested Talks
• MR14, Centre for Mathematical Sciences, Wilberforce Road, Cambridge
• bld31

Note that ex-directory lists are not shown.