You are cordially invited to the IPB COLLOQUIUM which will be held on Wednesday, 8 August 2018 at 12:00 in the “Zvonko Marić” lecture hall of the Institute of Physics Belgrade. The talk entitled
Thermal relaxations and the Mpemba effect
The Mpemba effect is a phenomenon when “hot can cool faster than cold” – a “shortcut” in relaxation to thermal equilibrium. It occurs when a physical system initially prepared at a hot temperature, cools faster than an identical system prepared at a colder temperature. The effect was discovered as a peculiarity of water. Despite following observations in granular gasses, magnetic alloys, and spin glasses, the effect is still most often referred to as an “oddity” of water, although it is widespread and general.
In this talk, we will describe how to define a Mpemba effect for an arbitrary physical system, and show how to quantify and estimate the probability of the Mpemba effect on a few examples. We will also explain that for specific physical systems we see this effect in the thermodynamic limit with a finite probability. Next, we will show that an enhanced Mpemba effect is possible for some choices of the initial temperatures, decreasing the cooling times considerably, and introduce a topological index that identifies the existence of such enhancement.