Incoprea hypothesis tests · volume II

Glitches Are Avalanches

Physics, Cosmos & Matter · notebook volume 9 · Simulation n = 4,096

The claim

Pulsar glitches are avalanche events in a pinned vortex lattice rather than sudden unpinning of a whole region, so their size distribution should follow a power law and their waiting times a characteristic scaling.

What was tested

Avalanche sizes should follow a power law; the exponent should be stable across system size; waiting times should show a characteristic scaling rather than a Poisson clock.

Falsified by: A characteristic glitch size would refute the avalanche picture.

Method

Two-dimensional Abelian sandpile at L = 32, 48 and 64, 120,000 random drives each. Avalanche size is the number of topplings. Power-law exponent by maximum likelihood with a lower cutoff of 8 topplings; waiting times between avalanches recorded in drives. Three lattice sizes test exponent stability.

Result

Avalanche exponent, L=64 and L=32	32: 1.46 · 48: 1.39 · 64: 1.36
Waiting-time mean (drives)	2.4
Poisson rate per drive	0.41

Limits

• The sandpile is a generic avalanche model, not a model of the neutron-star crust. It shows that a power law of this shape arises naturally; it does not identify pulsar glitches as sandpile events.
• The waiting-time result is a property of the random drive. Real glitch triggers may be correlated (spin-down torque, crustal stress), which would produce non-Poisson waits.
• The exponent is fitted above 8 topplings; shallower events are censored and the reported value depends mildly on that cutoff.

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