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REVIEW 3 major objections 4 minor 66 references

Fractional multi-phase transitions and nonlocal minimal partitions

T0 review · 3 major / 4 minor · reviewed 2026-08-15 · deepseek-v4-flash

Pith's one-line read Vectorial fractional Allen-Cahn limits are nonlocal minimal partitions, with regularity even if surface tensions violate the triangle inequality.

desk verdict Strong vectorial sharp-interface limit and nonlocal partition regularity, with one load-bearing proof omitted — worth refereeing hard. read the letter →

arxiv 2506.20226 v1 pith:DMHWARMJ submitted 2025-06-25 math.AP

classification math.AP MSC 35R1149Q2035B25
keywords fractionalAllen-Cahnnonlocalminimalpartitionsmultiple-wellpotentialsperimetersingularperturbationsphasetransitionspartialregularitysharp-interfacelimit
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

The paper establishes a sharp-interface limit for the vectorial fractional Allen-Cahn equation with an arbitrary number of wells. For exponents $s \in (0,1/2)$, it shows that any sequence of uniformly bounded-energy weak solutions converges to a partition of the domain into regions occupied by single phases, and that the limiting partition is stationary for a nonlocal interfacial energy in which the cost of an interface between phases $i$ and $j$ is proportional to $|a_i-a_j|^2$. The same conclusion holds for minimizers, with the limit minimizing the nonlocal energy under the assigned exterior data. Because the limiting coefficients are squared distances, they need not satisfy the usual triangle inequality, which is why the paper also develops a partial regularity theory for minimizing 3-partitions, including the case where a triangle inequality fails strictly. The upshot is a variational model of multi-phase interfaces that is genuinely nonlocal and has no local counterpart.

What carries the argument

Two mechanisms carry the argument. The first is the Caffarelli-Silvestre extension, which realizes $(-\Delta)^s$ as the Dirichlet-to-Neumann operator of the degenerate elliptic operator $-\mathrm{div}(z^{1-2s}\nabla\cdot)$ in the upper half-space; through it, solutions of the fractional Allen-Cahn equation become solutions of a boundary-reaction problem, and one obtains the monotonicity formula $\Theta_{s,\varepsilon}(v_\varepsilon,x_0,r)=r^{-(n-2s)}E_{s,\varepsilon}(v_\varepsilon,B_r^+(x_0))$ non-decreasing in $r$. That formula yields the clearing-out lemma, compactness of energy, and convergence of the energy densities. The second is the non-infiltration property for minimizing partitions, which says that a chamber with small enough volume fraction in a ball must disappear from the half-radius ball. Together with the classification of tangent maps and a quantitative stratification of the singular set, non-infiltration reduces the 3-phase problem, including the strictly inverse-triangle case, to the known regularity theory for almost-minimizers of the fractional perimeter.

What would settle it

Run the full vectorial extension argument on a three-well potential $W(z)=|z-a_1|^2|z-a_2|^2|z-a_3|^2$ with $s=0.3$ and symmetric Dirichlet data, and check numerically whether the normalized energy in half-balls obeys the monotonicity formula and whether small-energy half-balls clear to a single well; a concrete counterexample would be a bounded weak solution for which the normalized energy decreases at some scale, or whose small-energy limit retains two wells in a half-ball. More directly for Theorem 1.6, compute the limiting 3-partition in the plane for $\sigma_{12}>\sigma_{13}+\sigma_{23}$: the theorem predicts no triple junction and a smooth interface except possibly at isolated points, and a visible triple junction would refute it.

Watch

Extended reading notes

Core claim

On the paper's own terms, the central discovery is a compactness-and-identification theorem: under assumptions (H1)-(H3) on the multi-well potential, Theorem 1.1 proves that solutions $u_\varepsilon$ of $(-\Delta)^s u_\varepsilon + \varepsilon^{-2s}\nabla W(u_\varepsilon)=0$ in $\Omega$, with uniformly bounded fractional Allen-Cahn energy and converging exterior data, subconverge to $u_* = \sum_j \chi_{E^*_j} a_j$, where $E^*$ is a partition of $\Omega$ into open sets of finite $2s$-perimeter. The limit is stationary for the nonlocal partition energy $P^\sigma_{2s}$, meaning $\delta P^\sigma_{2s}(E^*,\Omega)[X]=0$ for every compactly supported field $X$; Theorem 1.2 adds that minimizers converge to minimizers of $P^\sigma_{2s}$. For minimizers, the paper then proves partial regularity: in the nearly homogeneous case, and for 3-partitions either under a strict triangle inequality or, for $s$ close to $1/2$, under a strict inverse triangle inequality, the interface is $C^\infty$ outside a relatively closed singular set of Hausdorff dimension at most $n-2$; in the inverse case the interface between the two dominant phases is contained in that singular set.

Load-bearing premise

The load-bearing premise is Theorem 3.2, the vectorial regularity-and-stationarity theorem for the degenerate Allen-Cahn boundary reaction whose proof is omitted because it is said to follow line by line from [51, Theorem 3.3]; if that extension failed, the clearing-out lemma, the convergence of energy densities, and the stationarity of the limiting partition would not be available.

Editorial extensions

If this is right

  • For $s \in (0,1/2)$, the sharp-interface limit of critical points is a stationary nonlocal partition, giving the first vectorial multi-well analogue of the scalar stationary-interface theorem.
  • Minimizers of the fractional Allen-Cahn energy converge to minimizers of $P^\sigma_{2s}$, so the nonlocal partition problem is a genuine variational limit of the phase-field model.
  • Transition layers have thickness of order $\varepsilon$, and away from the interface the solution approaches its limit at rate $\varepsilon^{2s}$, while the potential energy vanishes like $\varepsilon^{\min(4s,\alpha)}$ for every $\alpha \in (0,1)$.
  • In the nearly homogeneous coefficient regime, minimizing partitions are $C^\infty$ outside a singular set of Hausdorff dimension at most $n-2$, and locally finite when $n=2$.
  • For 3-partitions, even a strictly violated triangle inequality yields the same partial regularity for $s$ close enough to $1/2$, and the interface between the two phases with too-large a coefficient is itself contained in the singular set.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • The paper leaves the threshold $s_*(\sigma,n)$ in Theorem 1.6 implicit; a natural conjecture is that the inverse-triangle regularity holds for every $s \in (0,1/2)$, with the present proof limited by the quantitative convergence of normalized fractional perimeter to classical perimeter as $s \to 1/2$.
  • Since $\sigma_{ij}=|a_i-a_j|^2$ depends only on the squared distances between wells, one can design the well geometry to realize any $\ell^2$-embeddable matrix of coefficients, making the partition theory a laboratory for nonlocal clusters with exotic surface tensions.
  • In dimension two the authors conjecture that the interface between the two dominant phases is actually empty under a strict inverse triangle inequality; this is checkable by computing minimizers of $P^\sigma_{2s}$ with symmetric three-phase exterior data.
  • The optimal rate $\varepsilon^{\min(4s,1)}$ for the potential energy, which the paper leaves open, could be tested by constructing a matched asymptotic expansion of the two-well transition profile in a half-space.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

3 major / 4 minor

Summary. The paper studies the vectorial fractional Allen-Cahn system for s in (0,1/2) with multiple wells and proves that bounded-energy critical points converge, as the characteristic parameter tends to zero, to stationary nonlocal partitions for the energy P_sigma^{2s}, where sigma_ij = |a_i - a_j|^2. Minimizers converge to minimizing partitions. The paper then develops a regularity theory for stationary and minimizing nonlocal partitions: stationary partitions have open chambers and an interface of Minkowski codimension one, and minimizing partitions are C^∞ outside a singular set of Hausdorff dimension at most n-2 under a nearly homogeneous coefficient condition, or for 3-partitions under a strict triangle inequality. A headline result is the same partial regularity under a strict inverse triangle inequality for s close to 1/2, together with the statement that in that case the i0-j0 interface is contained in the singular set.

Significance. If the main theorems are correct, this is a substantial advance: it extends the scalar critical-point compactness of Millot--Sire--Wang to arbitrary vector-valued multi-well systems, and it initiates a regularity theory for nonlocal partitions with surface-tension coefficients that need not satisfy the triangle inequality, a phenomenon that has no counterpart in the local theory. The paper has real strengths: the coefficient matrix is derived parameter-free from the wells, the quantitative stratification arguments are laid out in detail, the non-infiltration propositions are proved, and many auxiliary estimates are given in full. The central caveat is that Theorem 3.2, on which the compactness, monotonicity, clearing-out, and stationarity steps all rest, is stated without proof and deferred to a scalar predecessor.

major comments (3)
  1. [Section 3.1, Theorem 3.2] The proof of Theorem 3.2 is omitted with the sentence "Since its proof follows from line to line the proof of [51, Theorem 3.3], we shall omit it." This is load-bearing: Corollary 3.3 (stationarity), Corollary 3.4 (monotonicity), Lemma 3.10 (clearing-out), Proposition 4.6, and ultimately Theorem 4.5 all use Theorem 3.2. The transfer from [51] is not automatic because [51] treats the scalar case d=1, whereas (3.9) is a system coupled through the boundary reaction grad W(v); scalar comparison and barrier arguments do not have an obvious vector analogue. Please supply a complete proof of Theorem 3.2, or a detailed step-by-step verification that identifies each scalar estimate in the proof of [51, Theorem 3.3] and explains why it applies componentwise to v_epsilon, and in particular why the boundary Holder estimate and the Hopf-type argument used in Corollary 3.8 hold for the system.
  2. [Section 6.2, Theorem 6.7(i)] The proof of the strong H^{s'} convergence in Theorem 6.7(i) is not written correctly. It bounds {u_k} in H^{s'}(Omega'') and then invokes a compact embedding H^{s''}(Omega'') subset of H^{s'}(Omega') for s'' < s'. The compact embedding goes in the opposite direction: H^{s'}(Omega'') embeds compactly into H^{s''}(Omega'') for s'' < s'. As written, the argument does not yield convergence in H^{s'}. The claim itself appears fixable: to prove convergence in H^{s'}, one should first obtain a uniform bound in H^t for some t in (s', min(2s,1/2)) and then apply compactness in H^{s'}; please rewrite the proof accordingly.
  3. [Section 7.3, Lemma 7.13, Eq. (7.37)] The displayed formula for Per(T,D_2) in (7.37) is incorrect. For T = {|x'| < 1/2, |x_n| < epsilon}, which is compactly contained in D_1, the relative perimeter in D_2 is 2 omega_{n-1} 2^{1-n} + 2 epsilon (n-1) omega_{n-1} 2^{2-n}, not (omega_{n-1} + 2 epsilon omega_{n-2}) 2^{2-n}: the lateral boundary contributes the sphere measure in R^{n-1}, proportional to (n-1) omega_{n-1}, not omega_{n-2}. The contradiction argument appears repairable because it only uses positivity of the epsilon-linear term and the value omega_{n-1}/2^{n-2} for the flat part, so a suitably chosen epsilon still yields a contradiction, but the formula and the choice of epsilon must be corrected.
minor comments (4)
  1. [Section 7.3] The second proof after Lemma 7.13 is headed "Proof of Theorem 1.5" but it proves Theorem 1.6; please correct the heading.
  2. [Section 7.3, Lemma 7.13] In the definition of the competitor F, the line "E_{j0} := H^c \ T" should read "F_{j0} := H^c \ T", since the sets of the competitor F are being defined.
  3. [Sections 6.1-6.2] In Corollary 6.6 and Theorem 6.7(ii), the notation W(v_k) should be W(u_k) for consistency with the Allen-Cahn equation and with Theorem 4.1.
  4. [Throughout] The manuscript contains several typos and formatting glitches, for example "Ginzburburg-Landau", "Corollay", and "V olume" in the table of contents; a careful copyedit is needed.

Circularity Check

0 steps flagged · score 1.0 of 10

No significant circularity; the main asymptotic and regularity arguments are self-contained, with one flagged omitted vectorial proof imported from a same-author scalar paper.

full rationale

The central derivation chain does not feed its conclusions back into its inputs. The limiting functional P^σ_2s is obtained by writing E_s(u,Ω) for Z-valued maps, with σ_ij=|a_i-a_j|^2 determined by the wells, and the stationarity δP^σ_2s=0 in Theorem 1.1 is derived from the Allen-Cahn variational equation via the extension procedure and a monotonicity/clearing-out argument, not assumed. No parameter is fitted to the target limit: the wells a_j and the potential W enter as hypotheses (H1)-(H3), and the constants c_i^W and κ_W are structural, not tuned to make the convergence statements true. Theorems 1.4-1.6 use the non-infiltration inequalities and known regularity of almost-minimizers of fractional perimeter, again without using the conclusion as an input. The one caveat that should be weighed is Section 3.1, Theorem 3.2: 'Since its proof follows from line to line the proof of [51, Theorem 3.3], we shall omit it.' This is a same-author citation ([51] includes Millot) and the omitted proof is load-bearing, since Corollary 3.3, Corollary 3.4, Lemma 3.10, and ultimately Theorem 4.5 rely on it. However, this is an unproven-transfer/missing-proof risk, not circularity: the paper does not define the regularity conclusion in terms of itself, and the cited scalar theorem has independent content. Under the hard rule that circularity requires an exhibited reduction (Eq. X = Eq. Y by construction, or a fitted parameter renamed as a prediction), no such reduction is present. Score 1 reflects the load-bearing self-citation with omitted vectorial justification, while the derivation itself is not circular.

Assumptions & free parameters 0 free parameters · 7 assumptions · 0 invented entities

The paper introduces no fitted or free parameters; the only numeric objects are constants whose existence is proved. The relevant axioms are standard tools from PDE and geometric measure theory plus the stated structural hypotheses. No new physical entities are postulated.

assumptions (7)
  • standard math Caffarelli-Silvestre extension realizes (-Delta)^s as a Dirichlet-to-Neumann operator for s in (0,1).
    Used throughout Section 2 to convert the nonlocal equation into a degenerate local boundary-reaction problem; cited to [14].
  • domain assumption Structural hypotheses (H1)-(H3) on the multi-well potential W: W is C^2, has exactly m nondegenerate wells, and satisfies radial p-growth bounds in every direction.
    Used to obtain L-infinity bounds, the maximum principle, clearing-out, and convergence rates; (H3) is a global growth hypothesis beyond the local structure at the wells.
  • domain assumption The coefficient matrix sigma belongs to S^2_m, meaning (sqrt(sigma_ij)) is ell-2-embeddable as Euclidean distances between m points.
    Required to represent the partition by an indicator function in H^s and to connect stationarity of the partition to stationarity of the phase map; automatic for Allen-Cahn limits and verified for the cases of Theorems 1.4-1.6.
  • standard math The regularity and stationarity theory of [51, Theorem 3.3] extends line-by-line to the vectorial setting, as stated without proof in Theorem 3.2.
    This imported theorem underpins the monotonicity formula, clearing-out property, and compactness used in the asymptotic analysis.
  • standard math The quantitative stratification framework of [32] applies to the density and control functions defined in Section 5.
    Used to prove the Minkowski dimension estimate for the singular set and the volume estimate for transition layers.
  • standard math Almost-minimal nonlocal boundary regularity from [27, Theorem 1.16] and higher-order regularity from [9, Theorem 5] hold in the two-phase regions.
    Used in Theorems 1.4-1.6 to upgrade the interface from C^{1,alpha} to C^infty once a non infiltration property reduces the partition locally to two phases.
  • standard math The normalized fractional perimeter (1-2s)P_{2s} converges to a multiple of the classical perimeter as s increases to 1/2.
    Used in Lemma 7.13 to rule out half-space tangent maps in the strict-inverse-triangle case for s close to 1/2; cited to [6,16,25].

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Cite this review

Pith. "Pith review of Fractional multi-phase transitions and nonlocal minimal partitions." pith.science (2026). https://pith.science/paper/DMHWARMJ

@misc{pith2026250620226,
  author       = {Pith},
  title        = {Pith review of: Fractional multi-phase transitions and nonlocal minimal partitions},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/DMHWARMJ}},
  note         = {Machine review of arXiv:2506.20226}
}
read the original abstract

This article is devoted to the study of certain models for phase transitions involving nonlocal energies. A first part is concerned with to the asymptotic analysis of a system of fractional elliptic equations of Allen-Cahn type as a characteristic small parameter tends to zero. It is shown that solutions converge to critical points of a nonlocal geometric energy defined over a class of partitions of the domain. A regularity analysis for solutions of the geometric problem is also performed, in the minimizing and non minimizing case. The limiting geometric problem involves generalized surface tension coefficients which might not satisfy the usual triangular inequality. A more detailed regularity analysis for minimizers is performed for 3-partitions, in particular in the case where one triangular inequality strictly holds in the reverse sense.

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Reference graph

Works this paper leans on

66 extracted references · 62 canonical work pages

  1. [51]

    MILLOT, Y

    V. MILLOT, Y. SIRE, K.WANG: Asymptotics for a fractional Allen-Cahn equation and stationary nonlocal minimal sur- faces,Arch. Rational Mech. Anal.231(2019), 1129–1216

  2. [1]

    ALBERTI, G

    G. ALBERTI, G. BELLETTINI: A non-local anisotropic model for phase transitions: asymptotic behaviour of rescaled energies,European J. Appl. Math.9(1998), 261–284

  3. [2]

    ALBERTI, G

    G. ALBERTI, G. BOUCHITT ´E, P. SEPPECHER: Un r ´esultat de perturbations singuli `eres avec la normeH 1/2,C. R. Acad. Sci. Paris S´er. I Math.319(1994), 333–338

  4. [3]

    ALBERTI, G

    G. ALBERTI, G. BOUCHITT ´E, P. SEPPECHER: Phase transition with the line-tension effect,Arch. Rational Mech. Anal. 144(1998), 1–46

  5. [4]

    ALMGREN:Existence and regularity almost everywhere of solutions to elliptic variational problems with constraints, Mem

    F.J. ALMGREN:Existence and regularity almost everywhere of solutions to elliptic variational problems with constraints, Mem. Amer. Math. Soc. 4 (165), 1976

  6. [5]

    AMBROSIO, A

    L. AMBROSIO, A. BRAIDES: Functionals defined on partitions in sets of finite perimeter. II. Semicontinuity, relaxation and homogenization,J. Math. Pures Appl.69(1990), 307–333

  7. [6]

    AMBROSIO, G

    L. AMBROSIO, G. DEPHILIPPIS, L. MARTINAZZI: Gamma-convergence of nonlocal perimeter functionals,Manuscripta Math.134(2011), 377–403

  8. [7]

    AMBROSIO, N

    L. AMBROSIO, N. FUSCO, D. PALLARA:Functions of Bounded Variation and Free Discontinuity Problems, Oxford University Press, New York (2000)

Show all 66 references
  1. [8]

    BALDO: Minimal interface criterion for phase transitions in mixtures of Cahn-Hilliard fluids,Ann

    S. BALDO: Minimal interface criterion for phase transitions in mixtures of Cahn-Hilliard fluids,Ann. Inst. H. Poincar ´e Anal. Non Lin´eaire7(1990), 67–90

  2. [9]

    BARRIOSBARRERA, A

    B. BARRIOSBARRERA, A. FIGALLI, E. VALDINOCI: Bootstrap regularity for integro-differential operators, and its appli- cation to nonlocal minimal surfaces,Ann. Scuola Norm. Sup. Pisa Cl. Sci.V ol. XIII (2014), 609–639. FRACTIONAL MULTI-PHASE TRANSITIONS61

  3. [10]

    B ´ETHUEL: Concentration sets for multiple equal-depth wells potentials in the 2D elliptic case, preprint arXiv:1802.01333

    F. B ´ETHUEL: Concentration sets for multiple equal-depth wells potentials in the 2D elliptic case, preprint arXiv:1802.01333

  4. [11]

    B ´ETHUEL: Asymptotics for two-dimensional vectorial Allen-Cahn systems, to appear inActa Math

    F. B ´ETHUEL: Asymptotics for two-dimensional vectorial Allen-Cahn systems, to appear inActa Math

  5. [12]

    BRONSARD, F

    L. BRONSARD, F. REITICH: On three-phase boundary motion and the singular limit of a vector-valued Ginzburg-Landau equation,Arch. Rational Mech. Anal.124(1993), 355– 379

  6. [13]

    CABR ´E, Y

    X. CABR ´E, Y. SIRE: Nonlinear equations for fractional Laplacians I: Regularity, maximum principles, and Hamiltonian estimates,Ann. Inst. H. Poincar ´e Anal. Non Lin´eaire31(2014), 23–53

  7. [14]

    CAFFARELLI, L

    L.A. CAFFARELLI, L. SILVESTRE: An extension problem related to the fractional Laplacian,Comm. Partial Differential Equations32(2007), 1245–1260

  8. [15]

    CAFFARELLI, J.M

    L.A. CAFFARELLI, J.M. ROQUEJOFFRE, O. SAVIN: Nonlocal minimal surfaces,Comm. Pure Appl. Math.63(2010), 1111–1144

  9. [16]

    CAFFARELLI, E

    L.A. CAFFARELLI, E. VALDINOCI: Uniform estimates and limiting arguments for nonlocal minimal surfaces,Calc. Var. Partial Differential Equations41(2011), 203–240

  10. [17]

    CAPUTO, N

    M.C. CAPUTO, N. GUILLEN: Regularity for non-local almost minimal boundaries and applications, preprint arXiv:1003.2470

  11. [18]

    CASELLI, E

    M. CASELLI, E. FLORIT-SIMON, J. SERRA: Yau’s conjecture for nonlocal minimal surfaces, preprint arXiv:2306.07100

  12. [19]

    CESARONI, M

    A. CESARONI, M. NOVAGA: Nonlocal minimal clusters in the plane,Nonlinear Anal.199(2020), 111945

  13. [20]

    H. CHAN, S. DIPIERRO, J. SERRA, E. VALDINOCI: Nonlocal approximation of minimal surfaces: optimal estimates from stability, preprintarXiv:2308.06328

  14. [21]

    CHODOSH, C

    O. CHODOSH, C. MANTOULIDIS: Minimal surfaces and the Allen-Cahn equation on 3-manifolds: index, multiplicity, and curvature estimates,Ann. of Math.191(2020), 213–328

  15. [22]

    CHEEGER, A

    J. CHEEGER, A. NABER: Quantitative stratification and the regularity of harmonic maps and minimal currents,Comm. Pure Appl. Math.66(2013), 965–990

  16. [23]

    CINTI, J

    E. CINTI, J. SERRA, E. VALDINOCI: Quantitative flatness results andBV-estimates for stable nonlocal minimal surfaces, J. Differential Geom.112(2019), 447–504

  17. [24]

    COLOMBO, F

    M. COLOMBO, F. MAGGI: Existence and almost everywhere regularity of isoperimetric clusters for fractional perimeters, Nonlinear Anal.153(2017), 243–274

  18. [25]

    D ´AVILA: On an open question about functions of bounded variation,Calc

    J. D ´AVILA: On an open question about functions of bounded variation,Calc. Var. Partial Differential Equations15(2002), 519–527

  19. [26]

    M. DEZA, M. LAURENT:Geometry of Cuts and Metrics. Algorithms and Combinatorics, Springer (1997)

  20. [27]

    DIPIERRO, E

    S. DIPIERRO, E. VALDINOCI, R. VILLA: On non-local almost minimal sets and an application to the non-local Massari’s problem, preprintarXiv:2411.07727

  21. [28]

    FABES, C.E

    E.B. FABES, C.E. KENIG, R.P. SERAPIONI: The local regularity of solutions of degenerate elliptic equations,Comm. Partial Differential Equations7(1982), 77–116

  22. [29]

    FALCONER:Fractal geometry

    K. FALCONER:Fractal geometry. Mathematical foundations and applications, John Wiley & Sons (2014)

  23. [30]

    FIGALLI, N

    A. FIGALLI, N. FUSCO, F. MAGGI, V. MILLOT, M. MORINI: Isoperimetry and stability properties of balls with respect to nonlocal energies,Comm. Math. Phys.336(2015), 441–507

  24. [31]

    FLORIT-SIMON: Weyl Law and convergence in the classical limit for min-max nonlocal minimal surfaces, preprint arXiv:2406.12162

    E. FLORIT-SIMON: Weyl Law and convergence in the classical limit for min-max nonlocal minimal surfaces, preprint arXiv:2406.12162

  25. [32]

    FOCARDI, A

    M. FOCARDI, A. MARCHESE, E. SPADARO: Improved estimate of the singular set of Dir-minimizingQ-valued functions via an abstract regularity result,J. Funct. Anal.268(2015), 3290-3325

  26. [33]

    FONSECA, L

    I. FONSECA, L. TARTAR: The gradient theory of phase transitions for systems with two potential wells,Proc. Roy. Soc. Edinburgh Sect. A111(1989), 89–102

  27. [34]

    FRANK, E.H

    R.L. FRANK, E.H. LIEBE, SEIRINGER, : Hardy-Lieb-Thirring inequalities for fractional Schr ¨odinger operators,J. Amer. Math. Soc.21(2008), 925–950

  28. [35]

    GARRONI, S

    A. GARRONI, S. M ¨ULLER: A variational model for dislocations in the line tension limit,Arch. Ration. Mech. Anal.181 (2006), 535–578

  29. [36]

    GASPAR, M

    P. GASPAR, M. A. GUARACO: The Allen-Cahn equation on closed manifolds,Calc. Var. Partial Differential Equations57 101, 2018

  30. [37]

    GONZ ´ALEZ: Gamma convergence of an energy functional related to the fractional Laplacian,Calc.Var

    M. GONZ ´ALEZ: Gamma convergence of an energy functional related to the fractional Laplacian,Calc.Var. Partial Differ- ential Equations36(2009), 173–210

  31. [38]

    GRISVARD:Elliptic problems in nonsmooth domains, Monographs and Studies in Mathematics, Pitman, Boston MA (1985)

    P. GRISVARD:Elliptic problems in nonsmooth domains, Monographs and Studies in Mathematics, Pitman, Boston MA (1985). 62 THOMAS GABARD AND VINCENT MILLOT

  32. [39]

    M. A. GUARACO: Min-max for phase transitions and the existence of embedded minimal hypersurfaces,J. Differential Geom.108(2018), 91–133

  33. [40]

    GURTIN: On a theory of phase transitions with interfacial energy,Arch

    M.E. GURTIN: On a theory of phase transitions with interfacial energy,Arch. Ration. Mech. Anal.87(1984), 187–212

  34. [41]

    HUTCHINSON, Y

    J.E. HUTCHINSON, Y. TONEGAWA: Convergence of phase interfaces in the van der Waals-Cahn-Hilliard theory,Calc. Var. Partial Differential Equations10(2000), 49–84

  35. [42]

    IMBERT: Level set approach for fractional mean curvature flows,Interfaces Free Bound.11(2009), 153–176

    C. IMBERT: Level set approach for fractional mean curvature flows,Interfaces Free Bound.11(2009), 153–176

  36. [43]

    IMBERT, P.E

    C. IMBERT, P.E. SOUGANIDIS: Phase field theory for fractional reaction-diffusion equations and applications, preprint arXiv:0907.5524

  37. [44]

    M. KAC, G. E. UHLENBECK, P. C. HEMMER: On the van der Waals theory of the vapor-liquid equilibrium. I. Discussion of a one-dimensional model,J. Mathematical Phys.4(1963), 216–228

  38. [45]

    LEONARDI: Infiltrations in immiscible fluids systems,Proc

    G.P. LEONARDI: Infiltrations in immiscible fluids systems,Proc. Roy. Soc. Edinburgh Sect. A131A (2001), 425–436

  39. [46]

    J. L. LEBOWITZ, O. PENROSE: Rigorous treatment of the van der Waals-Maxwell theory of the liquid-vapor transition,J. Mathematical Phys.7(1966), 98–113

  40. [47]

    F. MAGGI:Sets of finite perimeter and geometric variational problems: an introduction to Geometric Measure Theory, volume 135 of Cambridge Studies in Advanced Mathematics, Cambridge University Press, 2012

  41. [48]

    MATTILA:Geometry of sets and measures in Euclidean spaces, Cambridge Studies in Advanced Mathematics44, Cambridge University Press (1995)

    P. MATTILA:Geometry of sets and measures in Euclidean spaces, Cambridge Studies in Advanced Mathematics44, Cambridge University Press (1995)

  42. [49]

    MILLOT, M

    V. MILLOT, M. PEGON, A. SCHIKORRA: Partial regularity for fractional harmonic maps into spheres,Arch. Rational Mech. Anal.242(2021), 747–825

  43. [50]

    MILLOT, Y

    V. MILLOT, Y. SIRE: On a fractional Ginzburg-Landau equation and1/2-harmonic maps into spheres,Arch. Rational Mech. Anal.215(2015), 125–210

  44. [52]

    MODICA: The gradient theory of phase transitions and the minimal interface criterion,Arch

    L. MODICA: The gradient theory of phase transitions and the minimal interface criterion,Arch. Rational Mech. Anal.98 (1987), 123–142

  45. [53]

    MODICA, S

    L. MODICA, S. MORTOLA: Un esempio diΓ-convergenza,Boll. Un. Mat. Ital. B14(1977), 285–299

  46. [54]

    MOLCHANOV, E

    S.A. MOLCHANOV, E. OSTROVSKII: Symmetric stable processes as traces of degenerate diffusion processes,Theory Probab. Appl.14(1969), 128–131

  47. [55]

    MORGAN: Lowersemicontinuity of energy clusters,Proc

    F. MORGAN: Lowersemicontinuity of energy clusters,Proc. Roy. Soc. Edinburgh Sect. A127(1997), 819–822

  48. [56]

    NOVACK: Regularity for minimizers of a planar partitioning problem with cusps,Calc.Var

    M. NOVACK: Regularity for minimizers of a planar partitioning problem with cusps,Calc.Var. Partial Differential Equations 64(2025), no. 68

  49. [57]

    SAVIN, E

    O. SAVIN, E. VALDINOCI:Γ-convergence for nonlocal phase transitions,Ann. Inst. H. Poincar ´e Anal. Non Lin ´eaire29 (2012), 479–500

  50. [58]

    SAVIN, E

    O. SAVIN, E. VALDINOCI: Regularity of nonlocal minimal cones in dimension 2,Calc. Var. Partial Differential Equations 48(2013), 33–39

  51. [59]

    SERVADEI, E

    R. SERVADEI, E. VALDINOCI: Weak and viscosity solutions of the fractional Laplace equation,Publ. Mat.58(2014), 133–154

  52. [60]

    SIMON:Theorems on regularity and singularity of energy minimizing maps, Lectures in Mathematics ETH Z ¨urich, Birkh¨auser Verlag, Basel (1996)

    L. SIMON:Theorems on regularity and singularity of energy minimizing maps, Lectures in Mathematics ETH Z ¨urich, Birkh¨auser Verlag, Basel (1996)

  53. [61]

    STERNBERG: The effect of a singular perturbation on nonconvex variational problems,Arch

    P. STERNBERG: The effect of a singular perturbation on nonconvex variational problems,Arch. Rational Mech. Anal.101 (1988), 209–260

  54. [62]

    STERNBERG: Vector-valued local minimizers of nonconvex variational problems,Rocky Mountain J

    P. STERNBERG: Vector-valued local minimizers of nonconvex variational problems,Rocky Mountain J. Math.21(1991), 799–807

  55. [63]

    TERRACINI, G

    S. TERRACINI, G. VERZINI, A. ZILIO: Uniform H ¨older regularity with small exponent in competition-fractional diffusion systems,Discrete Contin. Dyn. Syst.34(2014), 2669–2691

  56. [64]

    TONEGAWA, N

    Y. TONEGAWA, N. WICKRAMASEKERA: Stable phase interfaces in the van der Waals-Cahn-Hilliard theory,J. Reine Angew. Math. (Crelle’s Journal)2012(2012), 191–210

  57. [65]

    WHITE: Existence of least-energy configurations of immiscible fluids,J

    B. WHITE: Existence of least-energy configurations of immiscible fluids,J. Geom. Anal.6(1996), 151–161

  58. [66]

    ZIEMER:Weakly differentiable functions, Graduate Texts in Mathematics, Springer-Verlag, New York (1989)

    W.P. ZIEMER:Weakly differentiable functions, Graduate Texts in Mathematics, Springer-Verlag, New York (1989). THOMASGABARD, LAMA, UNIVERSIT ´EPARISESTCR ´ETEIL, FRANCE Email address:thomas.gabard@u-pec.fr VINCENTMILLOT, LAMA, UNIVERSIT ´EPARISESTCR ´ETEIL, FRANCE Email address...

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