Moving, reproducing, and dying beyond Flatland: Malthusian flocks in dimensions d>2
File(s)PRL_clean_copy.pdf (402.3 KB)
Accepted version
Author(s)
Chen, Leiming
Lee, Chiu Fan
Toner, John
Type
Journal Article
Abstract
We show that “Malthusian flocks” – i.e., coherently moving collections of self-propelled entities (such as living creatures) which are being “born” and “dying” during their motion – belong to a new universality class in spatial dimensions
d
>
2
. We calculate the universal exponents and scaling laws of this new universality class to
O
(
ϵ
)
in an
ϵ
=
4
−
d
expansion, and find these are different from the “canonical” exponents previously conjectured to hold for “immortal” flocks (i.e., those without birth and death) and shown to hold for incompressible flocks in
d
>
2
. Our expansion should be quite accurate in
d
=
3
, allowing precise quantitative comparisons between our theory, simulations, and experiments.
d
>
2
. We calculate the universal exponents and scaling laws of this new universality class to
O
(
ϵ
)
in an
ϵ
=
4
−
d
expansion, and find these are different from the “canonical” exponents previously conjectured to hold for “immortal” flocks (i.e., those without birth and death) and shown to hold for incompressible flocks in
d
>
2
. Our expansion should be quite accurate in
d
=
3
, allowing precise quantitative comparisons between our theory, simulations, and experiments.
Date Acceptance
2020-07-21
Citation
Physical Review Letters
ISSN
0031-9007
Publisher
American Physical Society
Journal / Book Title
Physical Review Letters
Identifier
https://journals.aps.org/prl/accepted/02078Yd4Dd71757b48440159be15e1abc416e7102
Subjects
01 Mathematical Sciences
02 Physical Sciences
09 Engineering
General Physics
Publication Status
Accepted