MCF-stack: Special Solutions of Mean Curvature Flow
A growing Stacks-style reference collecting self-shrinkers, translators, self-expanders, ancient solutions, and other special solutions of mean curvature flow.
312 entries · 5 chapters · 155 sections · 1 manuscript · 137 references
Each catalogue entry records formulas or construction references, source-supported properties, and a picture. Drawings distinguish exact geometry, numerical ODE approximations, projections, and schematics.
Browse by properties →Ambient space · Topology, genus and ends · Embeddedness · Gaussian area and entropyWhat is mean curvature flow?
Mean curvature flow moves a curve, surface, or higher-dimensional submanifold in the direction of its mean curvature vector. For an immersion \(X:M^n\times I\to\mathbb R^{n+1}\), the geometric evolution equation is
Here \(\mathbf H\) is the mean curvature vector and \(\perp\) denotes projection onto the normal space. With an outward unit normal \(\nu\) and scalar mean curvature \(H=\operatorname{div}_M\nu\), we use \(\mathbf H=-H\nu\). A round sphere therefore shrinks under the flow.
The flow is the gradient flow of area: it decreases area for smooth closed submanifolds, but it can develop singularities. Special solutions provide explicit examples and models for understanding the geometry near singularities and at large scales.
What this stack collects
- Self-shrinkers: solutions that contract by dilation, normalized by \(\mathbf H+X^\perp/2=0\).
- Translators: solutions that move with a constant velocity \(V\), satisfying \(\mathbf H=V^\perp\).
- Self-expanders: solutions that expand by dilation, normalized by \(\mathbf H-X^\perp/2=0\).
- Other special solutions: ancient and eternal flows, stationary minimal submanifolds, and rotating or more general self-similar solutions.
An ancient solution exists for all times before some finite time; an eternal solution exists for all real times. These time domains do not by themselves imply self-similarity.
Following the idea of the Stacks Project, MCF-stack aims to connect examples, constructions, properties, and classification results through stable tags, cross-references, and precise source attribution. This is a growing reference, with hypotheses and proof status stated explicitly.
Selected examples
- Round shrinking spheres
- Angenent’s shrinking torus
- The bowl translator
- Expanding curves
- Graphical cone expanders
- The ancient Angenent oval
The reading collection consists of an introduction and four categories: shrinkers, translators, expanders, and other special flows. Each example includes a figure and precise references.
Table of contents
Chapter 1. Introduction358B9256A93C
- 1.1 Sources and conventions
35E9759B45E2
Chapter 2. Shrinkers766061837311
ℝ²
- 2.1 Closed planar shrinking curves (Abresch–Langer, 1986; Halldórsson, 2010; Drugan–Lee–X. H. Nguyen, 2017; Colding–Minicozzi II, 2019)
B4D1BD157D4B - 2.2 Spoon-shaped shrinking network (Chen–Guo, 2007; Chang, 2021)
E8ED05753059 - 2.3 Shrinking lens network (Chen–Guo, 2007; Chang, 2021)
5B73D42E7202 - 2.4 Shrinking fish network (Chen–Guo, 2007; Chang, 2021)
BAA362BD1D2D - 2.5 Three-ray shrinking star (Chen–Guo, 2007; Chang, 2021)
66EFFE766DF2 - 2.6 Four-ray shrinking star (Chen–Guo, 2007; Chang, 2021)
D3FA350D95E8 - 2.7 Five-ray shrinking star (Chen–Guo, 2007; Chang, 2021)
429D29F97379 - 2.8 Shrinking rocket network (Chen–Guo, 2007; Chang, 2021)
C8F779619BD0 - 2.9 Round shrinking spheres (Colding–Minicozzi II, 2009; Drugan–Lee–X. H. Nguyen, 2017)
2643D15A6912 - 2.10 Planes through the shrinker center (Colding–Minicozzi II, 2009; Drugan–Lee–X. H. Nguyen, 2017)
CB99B1567911 - 2.11 Nonclosed shrinking curves dense in an annulus
3A8C87C9FFF8 - 2.12 Cisgeminate-eye shrinker
AAF58D62FB97
ℝ³
- 2.13 Embedded rotational shrinking tori (Angenent, 1992; Colding–Minicozzi II, 2009; Drugan–Lee–X. H. Nguyen, 2017; Berchenko-Kogan, 2018)
EB7B6435F145 - 2.14 Chopp cubical shrinker candidate
90FE05D9053E - 2.15 Chopp octahedral shrinker candidate
EAAEF7E5907F - 2.16 Chopp punctured-torus saddle candidate
753FE61621D7 - 2.17 Chopp two-handled cone candidate
50368E5C98D8 - 2.18 Numerical four-handled cone shrinker candidate (Chopp, 1994; Angenent–Ilmanen–Chopp, 1995)
5684D97D637F - 2.19 Generalized shrinking cylinders
1A070FD35EB2 - 2.20 Rotational shrinking trumpet ends
72885E0FF22A - 2.21 Nguyen's one-ended shrinking saddles
EDE40E8E1379 - 2.22 One-ended high-genus shrinkers from sphere–plane gluing (Kapouleas–Kleene–Møller, 2011; Sun–Zhichao Wang, 2018)
2285B0C987A6 - 2.23 Closed shrinkers of large even genus via torus–sphere gluing (Colding–Minicozzi II, 2009; Møller, 2011; Drugan–Lee–X. H. Nguyen, 2017)
1AD8ABE5C210 - 2.24 Immersed rotational shrinking spheres (Drugan, 2013; Drugan–Lee–X. H. Nguyen, 2017)
2101D51F1E32 - 2.25 Drugan–Kleene immersed shrinking families
F2D20223E5E5 - 2.26 Shrinking ends asymptotic to isoparametric cones
33FBBB16A0B1 - 2.27 Ketover shrinkers with Platonic symmetry
B675C6112328 - 2.28 Variational embedded shrinking tori (Drugan–X. H. Nguyen, 2017; Chu–Sun, 2023)
7E48D8C7D552 - 2.29 Lens-shaped shrinking surface clusters
82C42A1C42B4 - 2.30 Closed shrinkers from spherical doubling
EB175520B015 - 2.31 Sun–Wang–Zhou shrinkers of arbitrarily large entropy
879F42A66D65 - 2.32 Noncompact shrinkers of every positive genus (Buzano–H. T. Nguyen–Schulz, 2021; Chu–Sun, 2023)
0E02104583BA - 2.33 Chu–Sun genus-one shrinkers below the shrinking doughnut
B050FA22AB2D - 2.34 Ilmanen–White two-ended shrinkers
C7322187A6FC - 2.35 Ketover self-shrinking doubled planes
8423ACEAF2E2 - 2.36 Flow-generated Platonic and polygonal shrinkers
1AF8BDC11238 - 2.37 Flow-generated sphere–plane shrinkers
036F44595178 - 2.38 Flow-generated three-ended shrinkers
5245200FA4A7 - 2.39 Shao–Zou shrinkers with any prescribed number of ends
EB2734BB2E46
ℝ⁴
- 2.40 Products of closed shrinking curves
44DD8966BC9A - 2.41 Higher-codimension spherical shrinkers (Smoczyk, 2005; Sun–Zhu, 2020)
6C99F82AA214 - 2.42 An embedded self-shrinking Möbius bundle (Lee–Mu-Tao Wang, 2007; Braxton–Lee–Zhu, 2026)
5D9025FCD9CD - 2.43 Compact periodic Lagrangian quadric shrinkers
6AFBAD1A608F - 2.44 Noncompact periodic Lagrangian shrinkers
9B86DFDA9217 - 2.45 The Clifford shrinking torus in four-space
CDFAEA3DDEF8 - 2.46 Cylinders over embedded rotational shrinking tori (Angenent, 1992; Berchenko-Kogan, 2018; Chen–Lee–Sun–Zhao, 2026)
99055D91C188 - 2.47 Park bi-rotational shrinking ends
51C4E786B6C8 - 2.48 Complete bi-rotational shrinking continuations
FDFAD175AF52
Higher dimensions (N ≥ 5)
Curved ambient spaces
Chapter 3. Translators2760875656EF
ℝ²
ℝ³
- 3.2 The rotational bowl translator (Clutterbuck–Schnürer–Schulze, 2005; Brendle–Choi, 2017; Hoffman–Ilmanen–Martín–White, 2019; Sun–Zhihan Wang, 2023)
38B2DD284E09 - 3.3 Rotational translating catenoids (Clutterbuck–Schnürer–Schulze, 2005; Hoffman–Ilmanen–Martín–White, 2019)
FEA31DEDC853 - 3.4 Periodic translating tridents (X. H. Nguyen, 2009; Hoffman–Ilmanen–Martín–White, 2019; Hoffman–Martín–White, 2019)
31505E08B028 - 3.5 Translators from grim-reaper configurations (X. H. Nguyen, 2010; X. H. Nguyen, 2012)
E83F92A45A1F - 3.6 Halldorsson helicoidal rotating translators
0FA3E75DD419 - 3.7 Finite-genus translators with three ends (Dávila–del Pino–X. H. Nguyen, 2015; Hoffman–Ilmanen–Martín–White, 2019)
8609A35E7601 - 3.8 Tilted grim-reaper cylinders
9A8E5E528EEB - 3.9 Strictly convex delta-wing translators
9BBF93D61D7A - 3.10 Translators with prescribed apex curvatures
DCD9F7224DF3 - 3.11 Scherkenoid translators (Hoffman–Ilmanen–Martín–White, 2019; Hoffman–Martín–White, 2019)
9E847D647A0C - 3.12 The pitchfork translator (Hoffman–Ilmanen–Martín–White, 2019; Hoffman–Martín–White, 2019; Gama–Martín–Møller, 2022; Martín–Sáez–Tsiamis–White, 2024)
64055D697644 - 3.13 Doubly periodic Scherk translators (Hoffman–Martín–White, 2019; Martín–Sáez–Tsiamis–White, 2024)
73DEA085F2F9 - 3.14 Helicoid-like translators (Hoffman–Martín–White, 2019; Martín–Sáez–Tsiamis–White, 2024)
0147E53C30CE - 3.15 Annuloid translators in slabs (Gama–Martín–Møller, 2022; Hoffman–Martín–White, 2023)
93A7D23F7FA3
ℝ⁴
- 3.16 Nonrotational entire convex translators
BD00A99565D1 - 3.17 Joyce–Lee–Tsui small-angle Lagrangian translators
16AF28E8CCDB - 3.18 Explicit rotating Lagrangian translators
5C21E6709CA8 - 3.19 Castro–Lerma Lagrangian translators from curve pairs
14F0E7012E88 - 3.20 Convex slab translators with polyhedral asymptotics
2F596CC616F1 - 3.21 Translators with an embedded rotational shrinking-torus end (Angenent, 1992; Sun–Zhihan Wang, 2023)
C8173134CEA6 - 3.22 Translators with high-genus spherical-doubling ends (Kapouleas–McGrath, 2020; Sun–Zhihan Wang, 2023)
A0A7AC0D200C - 3.23 Translators with general closed-shrinker ends
C44A1D57ECC3
Higher dimensions (N ≥ 5)
- 3.24 Su translators obtained by gluing grim cylinders
96393C1B9F17 - 3.25 Su–Wood Lagrangian translating helicoids
405ACD56C839 - 3.26 Su–Wood paired-profile translators
31FE1060BFF7 - 3.27 Nonconvex entire graphical translators
2E699B408ADA
Curved ambient spaces
- 3.28 Rotational translators in the hyperbolic-plane product
E33234341F7D - 3.29 Invariant translators in the Heisenberg group
750539FAA8AF - 3.30 Invariant translators in Sol geometry
2BC769F3A4AD - 3.31 Graphical translators over compact symmetric spaces (Fujii, 2021; Fujii–Koike, 2023)
1102596C432B - 3.32 Hyperbolic Killing translators and catenoids (de Lima–Ramos–dos Santos, 2023; de Lima–Ramos, 2026)
EA9BCA366717 - 3.33 Helicoidal rotators-translators in the hyperbolic-plane product
65C371A89575 - 3.34 Grim reapers in the hyperbolic-plane product
FB29EFBDEAE7 - 3.35 Parabolic Killing grim reapers in hyperbolic space
2C2BD4493223 - 3.36 Invariant translators in the special linear group
9C3485CD7693
Chapter 4. ExpandersEE91DF9C2CB0
ℝ²
ℝ³
- 4.4 Graphical expanders from general Lipschitz cones
152F8E9CDCFA - 4.5 Two-sheeted expanders of rotational double cones
ADE41440A542 - 4.6 One-sheeted expanders of rotational double cones
40FCBC562153 - 4.7 Rotational graphical expanders over round cones
A178E87D4BA0 - 4.8 One-sided expanders from mean-convex cones
5C7DD27422AD - 4.9 Mountain-pass self-expanders
665EA484B8DC - 4.10 Three-ended expanders of positive genus (Shao–Zou, 2025; Hoffman–Martín–White, 2026)
FC2EC5926764 - 4.11 Reported multiphase expanding surface constructions
BEE2570F7E0E - 4.12 Knotted self-expanders
38D2A75429F2
ℝ⁴
Higher dimensions (N ≥ 5)
Chapter 5. Other special flows52A98BA8F5C1
ℝ²
- 5.1 The ancient sine wave (Nakayama–Iizuka–Wadati, 1994; Angenent–You, 2018)
D8ADD5B24C33 - 5.2 Purely rotating curve-shortening solitons (Halldórsson, 2010; Halldórsson, 2011; D. J. Altschuler–S. J. Altschuler–Angenent–Wu, 2012)
3A1BA479B53D - 5.3 Rotating and expanding curve solitons (Halldórsson, 2010; D. J. Altschuler–S. J. Altschuler–Angenent–Wu, 2012)
E6DB29241FC5 - 5.4 Rotating and shrinking curve solitons (Halldórsson, 2010; D. J. Altschuler–S. J. Altschuler–Angenent–Wu, 2012)
3C52DD1F2A4E - 5.5 The Angenent oval as an explicit ancient flow
34E98635F82B - 5.6 Eternal curves from chains of grim reapers (Angenent–You, 2018; Choi–Seo–Su–Zhao, 2026)
321CCF32BF3F - 5.7 Immersed ancient curves from grim-reaper chains
F7D04537B40F - 5.8 Immersed ancient curves spanning a half-plane
DCA2FD176411 - 5.9 Convex ancient free-boundary flows in balls (Bourni–Langford, 2021; Bourni–Langford, 2022)
5E38E2470718 - 5.10 Compact nonconvex ancient spiral curves
F98988E964AC - 5.11 Ancient curves with mixed boundary conditions
4450DF902745 - 5.12 Ancient free-boundary curves in convex domains
1D94C677A1B5
ℝ³
- 5.13 Minimal surfaces as stationary mean curvature flows (Chopp, 1993; Mantegazza, 2011)
C9F0102B7272 - 5.14 Rotational degenerate neckpinch solutions
1E4AD3904D39 - 5.15 Helicoidal minimal surfaces as stationary flows
5BE3123E82F8 - 5.16 Eternal shrinking helices (D. J. Altschuler–S. J. Altschuler–Angenent–Wu, 2012; Stryker–Sun, 2019)
281263153F94 - 5.17 Rotating and translating curve solitons
9E45840987F2 - 5.18 Compact noncollapsed convex ancient ovals (Haslhofer–Hershkovits, 2013; Huisken–Sinestrari, 2014)
12F33FD70B5C - 5.19 Rotational collapsed ancient pancakes
68F95608F072 - 5.20 Ancient flows from unstable minimal hypersurfaces (Melko, 2010; Mramor–Payne, 2019; Choi–Huang–Lee, 2024)
C21B5E7431CB - 5.21 The eternal reapernoid
94DC745FE4C9 - 5.22 Non-self-similar ancient doughnuts
1E48CF8C9E56 - 5.23 Ancient pancakes with polyhedral asymptotics
AD25A77F6BAA - 5.24 Convex eternal flows that do not translate
E62279A82D37 - 5.25 Nonplanar eternal curves from grim reapers
AB3265DB1FB6 - 5.26 Non-self-similar flows emerging from cones
EA5C07CB7D0F - 5.27 Immortal annuli converging to a double plane
00966387D6EF
ℝ⁴
- 5.28 Stationary special Lagrangian necks (Joyce–Lee–Tsui, 2008; Imagi–Joyce–Oliveira dos Santos, 2014)
380EC54D3A30 - 5.29 Ancient torus curves in higher codimension (D. J. Altschuler–S. J. Altschuler–Angenent–Wu, 2012; Stryker–Sun, 2019)
B6082DA55C46 - 5.30 Ancient dense torus curves with irrational frequencies
E22AF7044670 - 5.31 Mean curvature evolution of the Whitney sphere
2E15631C1593 - 5.32 Ancient isoparametric flows in Euclidean space
F1B0B077B481 - 5.33 Ancient ovals with reduced symmetry
37474A54C83A - 5.34 Ancient stacked pancakes
9C9E3EBC47D4
Higher dimensions (N ≥ 5)
Curved ambient spaces
- 5.39 Ancient isoparametric flows in spheres
2DFF09123589 - 5.40 Eternal tori in perturbations of the round three-sphere
EF033313C0BB - 5.41 Isometric curve-shortening solitons in the hyperbolic plane
6E7783E99D53 - 5.42 Finite-time Lagrangian neck pinches with circle symmetry
06177EF7798F - 5.43 Lagrangian torus necks collapsing at infinite time
0AE8973A4338 - 5.44 Immortal compact flows converging to a double sphere
0806DD487DC4 - 5.45 Ancient flows from unstable free-boundary minimal hypersurfaces
1897F09E9330 - 5.46 Lagrangian sphere chains in Gibbons–Hawking spaces
2AB1CBD37191 - 5.47 Immortal curve shortening with nonunique geodesic limits
9C5BCCFA4320
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