Related Experiment Video
Updated: Jan 12, 2026
11:03
An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
9.0K
The geometry of jamming algorithms in the random Lorentz gas
Giampaolo Folena1, Patrick Charbonneau2,3, Peter K Morse4
1Dipartimento di Fisica, Sapienza Università di Roma, Roma 00185, Italy.
Summary
This study reveals that the geometric properties of energy landscapes define inherent structures in disordered matter, confirming the geometric nature of jamming. Algorithms explore these structures differently, impacting density but not the universal force distribution.
Area of Science:
- Physics
- Complex Systems
- Statistical Mechanics
Background:
- Deterministic optimization algorithms partition energy landscapes into inherent structures (ISs) and basins of attraction.
- Understanding hard sphere jamming, a model for disordered matter, hinges on whether these basins are geometrically defined.
Purpose of the Study:
- To investigate if geometric principles alone can define basins of attraction in energy landscapes.
- To explore the nature of inherent structures (ISs) in the hard-sphere jamming universality class.
Main Methods:
- Proposal of a geometric class of gradient descent-like algorithms.
- Application of these algorithms to the random Lorentz gas system, a model in the hard-sphere universality class.
Main Results:
- The statistics of inherent structures (ISs) are inherited from Poisson-Voronoi tessellations.
- Landscape roughness leads to a hierarchical organization of ISs, explored differently by various algorithms (greedy vs. reluctant).
- Despite differing densities favored by algorithms, ISs exhibit a universal force distribution.
Conclusions:
- The jamming universality class is confirmed to be geometric in nature.
- A dynamical Gardner transition's physical origin is identified within this framework.
Related Concept Videos
01:18First Law: Particles in Two-dimensional Equilibrium
14.0K
Recall that a particle in equilibrium is one for which the external forces are balanced. Static equilibrium involves objects at rest, and dynamic equilibrium involves objects in motion without acceleration; but it is important to remember that these conditions are relative. For instance, an object may be at rest when viewed from one frame of reference, but that same object would appear to be in motion when viewed by someone moving at a constant velocity.
Newton's first law tells us about...
Newton's first law tells us about...
14.0K
01:12Kinetic Theory of an Ideal Gas
4.6K
A mole is defined as the amount of any substance that contains as many molecules as there are atoms in exactly 12 grams of carbon-12. An Italian scientist Amedeo Avogadro (1776–1856) formed the hypothesis that equal volumes of gas at equal pressure and temperature contain equal numbers of molecules, independent of the type of gas. Later, the hypothesis was developed to form the SI unit for measuring the amount of any substance.
The number of molecules in one mole is called...
The number of molecules in one mole is called...
4.6K
01:10First Law: Particles in One-dimensional Equilibrium
7.9K
Newton's first law of motion states that a body at rest remains at rest, or if in motion, remains in motion at constant velocity, unless acted on by a net external force. It also states that there must be a cause for any change in velocity (a change in either magnitude or direction) to occur. This cause is a net external force. For example, consider what happens to an object sliding along a rough horizontal surface. The object quickly grinds to a halt, due to the net force of friction. If...
7.9K
01:27Gauss's Law: Planar Symmetry
9.3K
A planar symmetry of charge density is obtained when charges are uniformly spread over a large flat surface. In planar symmetry, all points in a plane parallel to the plane of charge are identical with respect to the charges. Suppose the plane of the charge distribution is the xy-plane, and the electric field at a space point P with coordinates (x, y, z) is to be determined. Since the charge density is the same at all (x, y) - coordinates in the z = 0 plane, by symmetry, the electric field at P...
9.3K
01:17Gauss's Law in Dielectrics
5.1K
Consider a polar dielectric placed in an external field. In such a dielectric, opposite charges on adjacent dipoles neutralize each other, such that the net charge within the dielectric is zero. When a polar dielectric is inserted in between the capacitor plates, an electric field is generated due to the presence of net charges near the edge of the dielectric and the metal plates interface. Since the external electrical field merely aligns the dipoles, the dielectric as a whole is neutral. An...
5.1K
01:28Symmetry in Maxwell's Equations
4.1K
Once the fields have been calculated using Maxwell's four equations, the Lorentz force equation gives the force that the fields exert on a charged particle moving with a certain velocity. The Lorentz force equation combines the force of the electric field and of the magnetic field on the moving charge. Maxwell's equations and the Lorentz force law together encompass all the laws of electricity and magnetism. The symmetry that Maxwell introduced into his mathematical framework may not be...
4.1K