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SLE Loop Measures Dapeng Zhan Michigan State University Geometry, - PowerPoint PPT Presentation

SLE Loop Measures Dapeng Zhan Michigan State University Geometry, Analysis and Probability May 8-12, 2017, KIAS 1 / 39 Background SLE = Schramm(1961-2008)-Loewner(1893-1968) evolution. 2 / 39 Background SLE =


  1. Previous works on SLE loops Werner used outer boundary of Brownian loop to construct SLE 8 / 3 loop with conformal restriction property. Kassel-Kenyon/Benoist-Dub´ edat constructed SLE 2 loop as scaling limit of the unicycle of a cycle-rooted spanning tree. The above are examples of Malliavin-Kontsevich-Suhov loop measure (c = 0, c = − 2), which is expected to exist for all c ≤ 1. 6 / 39

  2. Previous works on SLE loops Werner used outer boundary of Brownian loop to construct SLE 8 / 3 loop with conformal restriction property. Kassel-Kenyon/Benoist-Dub´ edat constructed SLE 2 loop as scaling limit of the unicycle of a cycle-rooted spanning tree. The above are examples of Malliavin-Kontsevich-Suhov loop measure (c = 0, c = − 2), which is expected to exist for all c ≤ 1. Sheffield-Werner constructed conformal loop ensemble (CLE κ ) for κ ∈ ( 8 3 , 8), which is a random collection of non-crossing loops in a simply connected domain. It is different from the SLE loop here. 6 / 39

  3. Previous works on SLE loops Werner used outer boundary of Brownian loop to construct SLE 8 / 3 loop with conformal restriction property. Kassel-Kenyon/Benoist-Dub´ edat constructed SLE 2 loop as scaling limit of the unicycle of a cycle-rooted spanning tree. The above are examples of Malliavin-Kontsevich-Suhov loop measure (c = 0, c = − 2), which is expected to exist for all c ≤ 1. Sheffield-Werner constructed conformal loop ensemble (CLE κ ) for κ ∈ ( 8 3 , 8), which is a random collection of non-crossing loops in a simply connected domain. It is different from the SLE loop here. Kemppainen-Werner constructed unrooted SLE κ loop measures in � C for κ ∈ (8 / 3 , 4] as the intensity measure of a nested CLE, which obius invariance of nested CLE on � is used to prove the M¨ C . 6 / 39

  4. Previous works on SLE loops SLE 8 / 3 bubble (loop rooted at a boundary point) was constructed by Lawler-Schramm-Werner as boundary of Brownian bubble. SLE κ bubble for κ ∈ ( 8 3 , 4] were constructed by Sheffield-Werner as a CLE κ loop conditioned to touch a boundary point. 7 / 39

  5. Previous works on SLE loops SLE 8 / 3 bubble (loop rooted at a boundary point) was constructed by Lawler-Schramm-Werner as boundary of Brownian bubble. SLE κ bubble for κ ∈ ( 8 3 , 4] were constructed by Sheffield-Werner as a CLE κ loop conditioned to touch a boundary point. Field-Lawler and Benoist-Dub´ edat have been working on the construction of SLE loops using different approaches. 7 / 39

  6. Main results We construct several types of SLE κ loop measures for κ ∈ (0 , 8). 8 / 39

  7. Main results We construct several types of SLE κ loop measures for κ ∈ (0 , 8). Highlights: 8 / 39

  8. Main results We construct several types of SLE κ loop measures for κ ∈ (0 , 8). Highlights: A new approach works for all κ ∈ (0 , 8), simple or nonsimple. 8 / 39

  9. Main results We construct several types of SLE κ loop measures for κ ∈ (0 , 8). Highlights: A new approach works for all κ ∈ (0 , 8), simple or nonsimple. CMP of SLE loops allows applying SLE-based results. 8 / 39

  10. Main results We construct several types of SLE κ loop measures for κ ∈ (0 , 8). Highlights: A new approach works for all κ ∈ (0 , 8), simple or nonsimple. CMP of SLE loops allows applying SLE-based results. Space-time homogeneity of SLE loop in natural parametrization. 8 / 39

  11. Main results We construct several types of SLE κ loop measures for κ ∈ (0 , 8). Highlights: A new approach works for all κ ∈ (0 , 8), simple or nonsimple. CMP of SLE loops allows applying SLE-based results. Space-time homogeneity of SLE loop in natural parametrization. Generalized restriction property similar to chordal SLE. 8 / 39

  12. Main results We construct several types of SLE κ loop measures for κ ∈ (0 , 8). Highlights: A new approach works for all κ ∈ (0 , 8), simple or nonsimple. CMP of SLE loops allows applying SLE-based results. Space-time homogeneity of SLE loop in natural parametrization. Generalized restriction property similar to chordal SLE. A 1 /d -self similar SLE κ process with stationary increments. 8 / 39

  13. Main results We construct several types of SLE κ loop measures for κ ∈ (0 , 8). Highlights: A new approach works for all κ ∈ (0 , 8), simple or nonsimple. CMP of SLE loops allows applying SLE-based results. Space-time homogeneity of SLE loop in natural parametrization. Generalized restriction property similar to chordal SLE. A 1 /d -self similar SLE κ process with stationary increments. Optimal H¨ older continuity of SLE with natural parametrization. 8 / 39

  14. Main results We construct several types of SLE κ loop measures for κ ∈ (0 , 8). Highlights: A new approach works for all κ ∈ (0 , 8), simple or nonsimple. CMP of SLE loops allows applying SLE-based results. Space-time homogeneity of SLE loop in natural parametrization. Generalized restriction property similar to chordal SLE. A 1 /d -self similar SLE κ process with stationary increments. Optimal H¨ older continuity of SLE with natural parametrization. Mckean’s dimension theorem for SLE (with factor d ). 8 / 39

  15. Relations with the previous works For κ = 8 / 3, the unrooted SLE 8 / 3 loop measure in Riemann surfaces agree with Werner’s SLE 8 / 3 loop measure. 9 / 39

  16. Relations with the previous works For κ = 8 / 3, the unrooted SLE 8 / 3 loop measure in Riemann surfaces agree with Werner’s SLE 8 / 3 loop measure. For κ = 2, the unrooted SLE 2 loop measure after normalization agrees with the SLE 2 measure by Kassel-Kenyon/Benoist-Dub´ edat. 9 / 39

  17. Relations with the previous works For κ = 8 / 3, the unrooted SLE 8 / 3 loop measure in Riemann surfaces agree with Werner’s SLE 8 / 3 loop measure. For κ = 2, the unrooted SLE 2 loop measure after normalization agrees with the SLE 2 measure by Kassel-Kenyon/Benoist-Dub´ edat. For κ ∈ (8 / 3 , 4], SLE κ loop measure in � C agrees with the loop measure by Kemppainen-Werner up to a multiplicative constant depending on κ . 9 / 39

  18. Relations with the previous works For κ = 8 / 3, the unrooted SLE 8 / 3 loop measure in Riemann surfaces agree with Werner’s SLE 8 / 3 loop measure. For κ = 2, the unrooted SLE 2 loop measure after normalization agrees with the SLE 2 measure by Kassel-Kenyon/Benoist-Dub´ edat. For κ ∈ (8 / 3 , 4], SLE κ loop measure in � C agrees with the loop measure by Kemppainen-Werner up to a multiplicative constant depending on κ . For κ ∈ [8 / 3 , 4], the SLE κ bubble measure agrees with the bubble measures by Lawler-Schramm-Werner and Sheffield-Werner up to a multiplicative constant. 9 / 39

  19. Relations with the previous works For κ = 8 / 3, the unrooted SLE 8 / 3 loop measure in Riemann surfaces agree with Werner’s SLE 8 / 3 loop measure. For κ = 2, the unrooted SLE 2 loop measure after normalization agrees with the SLE 2 measure by Kassel-Kenyon/Benoist-Dub´ edat. For κ ∈ (8 / 3 , 4], SLE κ loop measure in � C agrees with the loop measure by Kemppainen-Werner up to a multiplicative constant depending on κ . For κ ∈ [8 / 3 , 4], the SLE κ bubble measure agrees with the bubble measures by Lawler-Schramm-Werner and Sheffield-Werner up to a multiplicative constant. The simple SLE κ loops for κ ∈ (0 , 4] give examples of MKS loop measures with c = (6 − κ )(3 κ − 8) ∈ ( −∞ , 1]. 2 κ 9 / 39

  20. The first attempt A whole-plane SLE κ curve from 0 to ∞ may be constructed by the following procedure. Run a radial SLE κ curve in the simply connected domain � C \ {| z | ≤ ε } from ε to ∞ , and take the limit as ε → 0. 10 / 39

  21. The first attempt A whole-plane SLE κ curve from 0 to ∞ may be constructed by the following procedure. Run a radial SLE κ curve in the simply connected domain � C \ {| z | ≤ ε } from ε to ∞ , and take the limit as ε → 0. This inspires us to define SLE κ loop rooted at 0 by the following approach: run a chordal SLE κ curve in � C \ {| z | ≤ ε } from ε to − ε , and then let ε → 0. This procedure does not work because of the following reason. As SLE κ for κ ∈ (0 , 8) is not space-filing, almost surely the curve avoids ∞ , i.e., the curve is bounded. By scaling property, we end up with a single point by taking the limit ε → 0. 10 / 39

  22. The first attempt A whole-plane SLE κ curve from 0 to ∞ may be constructed by the following procedure. Run a radial SLE κ curve in the simply connected domain � C \ {| z | ≤ ε } from ε to ∞ , and take the limit as ε → 0. This inspires us to define SLE κ loop rooted at 0 by the following approach: run a chordal SLE κ curve in � C \ {| z | ≤ ε } from ε to − ε , and then let ε → 0. This procedure does not work because of the following reason. As SLE κ for κ ∈ (0 , 8) is not space-filing, almost surely the curve avoids ∞ , i.e., the curve is bounded. By scaling property, we end up with a single point by taking the limit ε → 0. This observation also gives an evidence that the law of an SLE κ loop can not be a probability measure. 10 / 39

  23. Kernel We now construct rooted SLE loops with CMP. To understand CMP rigorously, we use the notion kernel from modern probability. 11 / 39

  24. Kernel We now construct rooted SLE loops with CMP. To understand CMP rigorously, we use the notion kernel from modern probability. Given measurable spaces ( U, U ) and ( V, V ), a kernel ν from U to V is a map ν : U × V → [0 , ∞ ] such that 11 / 39

  25. Kernel We now construct rooted SLE loops with CMP. To understand CMP rigorously, we use the notion kernel from modern probability. Given measurable spaces ( U, U ) and ( V, V ), a kernel ν from U to V is a map ν : U × V → [0 , ∞ ] such that (i) for every u ∈ U , ν ( u, · ) is a measure on V ; (ii) for every F ∈ V , ν ( · , F ) is U -measurable. 11 / 39

  26. Kernel We now construct rooted SLE loops with CMP. To understand CMP rigorously, we use the notion kernel from modern probability. Given measurable spaces ( U, U ) and ( V, V ), a kernel ν from U to V is a map ν : U × V → [0 , ∞ ] such that (i) for every u ∈ U , ν ( u, · ) is a measure on V ; (ii) for every F ∈ V , ν ( · , F ) is U -measurable. The kernel ν is said to be σ -finite if V = � F n for F n ∈ V such that ν ( u, F n ) < ∞ for all u ∈ U and n ∈ N . 11 / 39

  27. Kernel We now construct rooted SLE loops with CMP. To understand CMP rigorously, we use the notion kernel from modern probability. Given measurable spaces ( U, U ) and ( V, V ), a kernel ν from U to V is a map ν : U × V → [0 , ∞ ] such that (i) for every u ∈ U , ν ( u, · ) is a measure on V ; (ii) for every F ∈ V , ν ( · , F ) is U -measurable. The kernel ν is said to be σ -finite if V = � F n for F n ∈ V such that ν ( u, F n ) < ∞ for all u ∈ U and n ∈ N . Given a σ -finite measure µ on U and a σ -finite kernel from U to V , we may define a measure µ ⊗ ν on U × V such that � µ ⊗ ν ( E × F ) = ν ( u, F ) dµ ( u ) , E ∈ U , F ∈ V . E � We use ν ( u, · ) µ ( du ) to denote the margimal of µ ⊗ ν on V . 11 / 39

  28. Kernel We now construct rooted SLE loops with CMP. To understand CMP rigorously, we use the notion kernel from modern probability. Given measurable spaces ( U, U ) and ( V, V ), a kernel ν from U to V is a map ν : U × V → [0 , ∞ ] such that (i) for every u ∈ U , ν ( u, · ) is a measure on V ; (ii) for every F ∈ V , ν ( · , F ) is U -measurable. The kernel ν is said to be σ -finite if V = � F n for F n ∈ V such that ν ( u, F n ) < ∞ for all u ∈ U and n ∈ N . Given a σ -finite measure µ on U and a σ -finite kernel from U to V , we may define a measure µ ⊗ ν on U × V such that � µ ⊗ ν ( E × F ) = ν ( u, F ) dµ ( u ) , E ∈ U , F ∈ V . E � We use ν ( u, · ) µ ( du ) to denote the margimal of µ ⊗ ν on V . Use ν ← − ⊗ µ if we want to switch the order of U and V . 11 / 39

  29. Kernel We may describe the sampling of ( X, Y ) according to the measure µ ⊗ ν in two steps. First, “sample” X according to the measure µ . Second, “sample” Y according to the kernel ν and the value of X . 12 / 39

  30. Kernel We may describe the sampling of ( X, Y ) according to the measure µ ⊗ ν in two steps. First, “sample” X according to the measure µ . Second, “sample” Y according to the kernel ν and the value of X . Caution : After the second step, the marginal measure of X is changed unless ν is µ -a.s. a probability kernel, i.e., ν ( u, V ) = 1 for µ -a.s. u ∈ U . In fact, if ν is finite, then the new marginal measure of X is absolutely continuous w.r.t. the old law: µ , and the RN derivative is ν ( · , V ). 12 / 39

  31. CMP and kernel The rigorous statement of the CMP for a chordal SLE κ measure µ # D ; a → b in D from a to b is as follows. Let T b be the time that the curve ends at b . If τ is a stopping time, then K τ ( µ # D ; a → b | { τ<T b } )( dγ τ ) ⊕ µ # D ( γ τ ; b );( γ τ ) tip → b ( dγ τ ) = µ # D ; a → b | { τ<T b } , 13 / 39

  32. CMP and kernel The rigorous statement of the CMP for a chordal SLE κ measure µ # D ; a → b in D from a to b is as follows. Let T b be the time that the curve ends at b . If τ is a stopping time, then K τ ( µ # D ; a → b | { τ<T b } )( dγ τ ) ⊕ µ # D ( γ τ ; b );( γ τ ) tip → b ( dγ τ ) = µ # D ; a → b | { τ<T b } , where K τ ( γ ) is the truncation of γ at time τ . µ ⊕ ν is the pushforward of µ ⊗ ν under the concatenation map ( β, γ ) �→ β ⊕ γ . D ( γ τ ; b ) is the connected component of D \ γ τ whose boundary contains b and ( γ τ ) tip , the tip of γ τ . µ # D ( γ τ ; b );( γ τ ) tip → b is a chordal SLE κ measure in D ( γ τ ; b ). 13 / 39

  33. CMP and kernel Using the same spirit, we may rigorously define the CMP for an SLE κ z in � loop measure µ 1 C rooted at z as follows. Let T z be the time that the loop returns to z . If τ is a nontrivial stopping time, then z | { τ<T z } )( dγ τ ) ⊕ µ # K τ ( µ 1 C ( γ τ ; z );( γ τ ) tip → z ( dγ τ ) = µ 1 z | { τ<T z } , � 14 / 39

  34. CMP and kernel Using the same spirit, we may rigorously define the CMP for an SLE κ z in � loop measure µ 1 C rooted at z as follows. Let T z be the time that the loop returns to z . If τ is a nontrivial stopping time, then z | { τ<T z } )( dγ τ ) ⊕ µ # K τ ( µ 1 C ( γ τ ; z );( γ τ ) tip → z ( dγ τ ) = µ 1 z | { τ<T z } , � where K τ ( γ ) and µ ⊕ ν have the same meaning as before. C ( γ τ ; z ) is the connected component of � � C \ γ τ whose boundary contains z and ( γ τ ) tip , the tip of γ τ . µ # C ( γ τ ; z );( γ τ ) tip → z is a chordal SLE κ measure in � C ( γ τ ; z ). � 14 / 39

  35. Natural parametrization Our construction of SLE loops is built on the natural parametrization of SLE developed by Lawler, Sheffield, Zhou, Rezaei, Viklund.... 15 / 39

  36. Natural parametrization Our construction of SLE loops is built on the natural parametrization of SLE developed by Lawler, Sheffield, Zhou, Rezaei, Viklund.... SLE defined from Loewner’s equation has the built-in capacity parametrization (CP). Lawler initiated the study of natural parametrization (NP) in order to improve the scaling limits results about SLE to capture the original length of the random lattice curves. The existence of NP of SLE for κ ∈ (0 , 8) was proved in [Lawler-Sheffield] and [Lawler-Zhou]. Lawler and Viklund proved that LERW with natural length converges to SLE 2 with NP. 15 / 39

  37. Natural parametrization Our construction of SLE loops is built on the natural parametrization of SLE developed by Lawler, Sheffield, Zhou, Rezaei, Viklund.... SLE defined from Loewner’s equation has the built-in capacity parametrization (CP). Lawler initiated the study of natural parametrization (NP) in order to improve the scaling limits results about SLE to capture the original length of the random lattice curves. The existence of NP of SLE for κ ∈ (0 , 8) was proved in [Lawler-Sheffield] and [Lawler-Zhou]. Lawler and Viklund proved that LERW with natural length converges to SLE 2 with NP. Lawler and Rezaei proved that NP of SLE agrees with the d -dimensional Minkowski content of SLE, where d = 1 + κ 8 is the Hausdorff dimension of SLE ([Beffara]). So NP of SLE is determined by the curve itself, and independent of the domain or equation. 15 / 39

  38. Minkowski content measure Now we recall the Minkowski content and introduce the Minkowski content measure. We fix d ∈ (1 , 2). Let S ⊂ C be a closed set. The ( d -dimensional) Minkowski content of S is defined to be ε ↓ 0 ε d − 2 A ( S ε ) , Cont( S ) = lim where A is the area measure, and S ε is the ε -neighborhood of S . 16 / 39

  39. Minkowski content measure Now we recall the Minkowski content and introduce the Minkowski content measure. We fix d ∈ (1 , 2). Let S ⊂ C be a closed set. The ( d -dimensional) Minkowski content of S is defined to be ε ↓ 0 ε d − 2 A ( S ε ) , Cont( S ) = lim where A is the area measure, and S ε is the ε -neighborhood of S . Definition Let S ⊂ C . Suppose M is a measure supported by S such that for every compact set K ⊂ C , Cont( K ∩ S ) = M ( K ) < ∞ . Then we say that M is the Minkowski content measure on S , or S possesses Minkowski content measure. We will use M S to denote this measure. 16 / 39

  40. Space-time homogeneity Lawler conjectured that an SLE κ loop measure should satisfy space-time homogeneity: Suppose γ follows the SLE κ loop measure µ 1 z rooted at z , and is parameterized periodically by its Minkowski content measure. Then for any deterministic number a ∈ R , if we reroot the loop at γ ( a ), i.e., we define a new loop: T a ( γ )( t ) := z + γ ( a + t ) − γ ( a ), then the “law” of the new loop T a ( γ ) is still µ 1 z . 17 / 39

  41. Space-time homogeneity Lawler conjectured that an SLE κ loop measure should satisfy space-time homogeneity: Suppose γ follows the SLE κ loop measure µ 1 z rooted at z , and is parameterized periodically by its Minkowski content measure. Then for any deterministic number a ∈ R , if we reroot the loop at γ ( a ), i.e., we define a new loop: T a ( γ )( t ) := z + γ ( a + t ) − γ ( a ), then the “law” of the new loop T a ( γ ) is still µ 1 z . Here we say that a loop γ is parameterized periodically by its Minkowski content measure if γ is defined on R with period T = Cont( γ ) such that for any a ≤ b ≤ a + T , Cont( γ ([ a, b ]) = b − a . 17 / 39

  42. Minkowski content measure The work by Lawler and Rezaei showed that a chordal SLE κ curve in H := { z : Im z > 0 } a.s. possesses Minkowski content measure, which is the pushforward measure of NP under the curve function. Moreover, the measure is supported by H , and is parameterizable for the curve. 18 / 39

  43. Minkowski content measure The work by Lawler and Rezaei showed that a chordal SLE κ curve in H := { z : Im z > 0 } a.s. possesses Minkowski content measure, which is the pushforward measure of NP under the curve function. Moreover, the measure is supported by H , and is parameterizable for the curve. Minkowski content measure satisfies conformal covariance with factor d . This means that, if S possesses Minkowski content measure M S , and if f is a conformal map defined on a domain D ⊃ S , then f ( S ) also possesses Minkowski content measure, which is absolutely continuous w.r.t. f ∗ ( M S ), and the RN derivative is | f ′ ( f − 1 ( · )) | d . 18 / 39

  44. Minkowski content measure The work by Lawler and Rezaei showed that a chordal SLE κ curve in H := { z : Im z > 0 } a.s. possesses Minkowski content measure, which is the pushforward measure of NP under the curve function. Moreover, the measure is supported by H , and is parameterizable for the curve. Minkowski content measure satisfies conformal covariance with factor d . This means that, if S possesses Minkowski content measure M S , and if f is a conformal map defined on a domain D ⊃ S , then f ( S ) also possesses Minkowski content measure, which is absolutely continuous w.r.t. f ∗ ( M S ), and the RN derivative is | f ′ ( f − 1 ( · )) | d . In particular, we see that SLE κ curve in any simply connected domain possesses Minkowski content measure. 18 / 39

  45. Two-sided radial SLE and Green’s function We will uses the decomposition of chordal SLE κ in terms of two-sided radial SLE κ initiated by Laurie Field. 19 / 39

  46. Two-sided radial SLE and Green’s function We will uses the decomposition of chordal SLE κ in terms of two-sided radial SLE κ initiated by Laurie Field. A two-sided radial SLE κ curve grows in a simply connected domain from one boundary point to another boundary point passing through a marked interior point. 19 / 39

  47. Two-sided radial SLE and Green’s function We will uses the decomposition of chordal SLE κ in terms of two-sided radial SLE κ initiated by Laurie Field. A two-sided radial SLE κ curve grows in a simply connected domain from one boundary point to another boundary point passing through a marked interior point. It may be viewed as a chordal SLE κ curve conditioned on the event that it passes through the marked interior point. 19 / 39

  48. Two-sided radial SLE and Green’s function We will uses the decomposition of chordal SLE κ in terms of two-sided radial SLE κ initiated by Laurie Field. A two-sided radial SLE κ curve grows in a simply connected domain from one boundary point to another boundary point passing through a marked interior point. It may be viewed as a chordal SLE κ curve conditioned on the event that it passes through the marked interior point. The Green’s function for a chordal SLE κ curve is the limit as ε → 0 of the probability of the event that a chordal SLE κ curve visits a disc of radius ε divided by the scaling factor ε 2 − d . 19 / 39

  49. Two-sided radial SLE and Green’s function We will uses the decomposition of chordal SLE κ in terms of two-sided radial SLE κ initiated by Laurie Field. A two-sided radial SLE κ curve grows in a simply connected domain from one boundary point to another boundary point passing through a marked interior point. It may be viewed as a chordal SLE κ curve conditioned on the event that it passes through the marked interior point. The Green’s function for a chordal SLE κ curve is the limit as ε → 0 of the probability of the event that a chordal SLE κ curve visits a disc of radius ε divided by the scaling factor ε 2 − d . We use µ # D ; a → b , ν # D ; a → z → b and G D ; a → b to denote chordal SLE, two-sided radial SLE and chordal SLE Green’s function. 19 / 39

  50. Decomposition of SLE Field proved that, for κ ∈ (0 , 4], a bounded domain D with analytic boundary, and distinct points a, b ∈ ∂D , � ν # D ; a → z → b G D ; a → b ( z ) A ( dz ) = Cont · µ # D ; a → b . D 20 / 39

  51. Decomposition of SLE Field proved that, for κ ∈ (0 , 4], a bounded domain D with analytic boundary, and distinct points a, b ∈ ∂D , � ν # D ; a → z → b G D ; a → b ( z ) A ( dz ) = Cont · µ # D ; a → b . D This means, if one integrates the laws of two-sided radial SLE κ curves in D from a to b passing through different interior points against the Green’s function for the chordal SLE κ curve in D from a to b , then one gets the law of a chordal SLE κ curve in D from a to b biased by the Minkowski content of the whole curve. 20 / 39

  52. Decomposition of SLE Field’s result was later extended to all κ ∈ (0 , 8) in a more general form. Theorem (Z, 2016) Let κ ∈ (0 , 8) . Let D be a simply connected domain with two distinct prime ends a and b . Then D ; a → z → b ( dγ ) ← − µ # D ; a → b ( dγ ) ⊗ M γ ; D ( dz ) = ν # ⊗ ( G D ; a → b · A )( dz ) . By looking at the first marginal measure, we recover Field’s result. 21 / 39

  53. Decomposition of SLE Field’s result was later extended to all κ ∈ (0 , 8) in a more general form. Theorem (Z, 2016) Let κ ∈ (0 , 8) . Let D be a simply connected domain with two distinct prime ends a and b . Then D ; a → z → b ( dγ ) ← − µ # D ; a → b ( dγ ) ⊗ M γ ; D ( dz ) = ν # ⊗ ( G D ; a → b · A )( dz ) . By looking at the first marginal measure, we recover Field’s result. The above results show that the law of a chordal SLE κ curve in D from a to b may be constructed by integrating the laws of two-sided radial SLE κ curves in D from a to b passing through different points z against the Green’s function for the chordal SLE κ , and then unweighting the integrated measure by the Minkowski content of the curve. 21 / 39

  54. Construction of rooted SLE loop The construction of rooted SLE κ loops is inspired by the above observation. Since an SLE κ loop rooted at z may be viewed as a degenerate chordal SLE κ in � C from z to z , we expect that its law can be constructed by integrating the laws of degenerate two-sided radial SLE κ curves in � C from z to z passing through different points w against some suitable function, and then unweighting the integrated measure by the Minkowski content. 22 / 39

  55. Construction of rooted SLE loop The construction of rooted SLE κ loops is inspired by the above observation. Since an SLE κ loop rooted at z may be viewed as a degenerate chordal SLE κ in � C from z to z , we expect that its law can be constructed by integrating the laws of degenerate two-sided radial SLE κ curves in � C from z to z passing through different points w against some suitable function, and then unweighting the integrated measure by the Minkowski content. A degenerate two-sided radial SLE κ curve in � C from z to z passing through w is a two-sided whole-plane SLE κ curve, which is composed of two arms connecting two points in � C . A two-sided whole-plane SLE κ satisfies some CMP such that two-sided whole-plane : two-sided radial = whole-plane : radial . 22 / 39

  56. Rooted loops I Below is the main theorem on rooted SLE loop measure µ 1 z : the superscript 1 denotes the number of root; the subscript z is the root. Theorem Let G C ( w ) = | w | − 2(2 − d ) , w ∈ C \ { 0 } . Let ν # z ⇋ w denote the law of the two-sided whole-plane SLE κ curve from z to z passing through w (modulo a time change). Define � z = Cont( · ) − 1 · ν # µ 1 z ⇋ w G C ( w − z ) A ( dw ) , z ∈ C . C \{ z } Then we have the following facts: 23 / 39

  57. Rooted loops II Theorem z is supported by non-degenerate loops in � (i) Each µ 1 C rooted at z which possess Minkowski content measure that is parameterizable. Moreover, we have the decomposition formula z ⇋ w ( dγ ) ← − z ( dγ ) ⊗ M γ ( dw ) = ν # µ 1 ⊗ G C ( w − z ) · A ( dw ) , z ∈ C . (ii) Each µ 1 z satisfies CMP. (iii) Each µ 1 z satisfies the space-time homogeneity. obius covariance: W ( µ 1 z ) = | W ′ ( z ) | 2 − d µ 1 (iv) M¨ W ( z ) . (v) For each r > 0 , (a) µ 1 z ( { γ : diam( γ ) > r } ) < ∞ ; (b) µ 1 z ( { γ : Cont( γ ) > r } ) < ∞ . (vi) If a measure µ ′ supported by non-degenerate loops rooted at z satisfies (II) and (V.a), then µ ′ = cµ 1 z for some c ≥ 0 . 24 / 39

  58. Self similarity and stationary increments There is an interseting byproduct of the SLE loop measures: H¨ older continuity and dimension property of SLE with NP. 25 / 39

  59. Self similarity and stationary increments There is an interseting byproduct of the SLE loop measures: H¨ older continuity and dimension property of SLE with NP. Below is a list of previous works. Rohde and Schramm proved that SLE in CP is H¨ older continuous for κ � = 8. Lind improved the H¨ older exponents of SLE in CP, which was later proved to be optimal by Lawler and Viklund. Werness proved that, for κ ≤ 4, for any α < 1 /d , an SLE κ curve may be reparametrized to be α -H¨ older continuous. Lawler and Rezaei proved that, if SLE κ curve γ is parameterized by CP, and if Θ t is such that γ ◦ Θ − 1 is γ parameterized by NP, then Θ is H¨ older continuous. No result on the H¨ older continuity of SLE with NP was known. 25 / 39

  60. If we apply the map z �→ 1 /z to the formula: 0 ⇋ w ( dγ ) ← − ⊗ ( | w | − 2(2 − d ) · A )( dw ) , 0 ( dγ ) ⊗ M γ ( dw ) = ν # µ 1 then we get ∞ ⇋ w ( dγ ) ← − ∞ ( dγ ) ⊗ M γ ( dw ) = ν # µ 1 ⊗ A ( dw ) . Since ν # ∞ ⇋ w = w + ν # ∞ ⇋ 0 , using the above formula, we can prove that, if a two-sided whole-plane SLE κ curve γ with law ν # ∞ ⇋ 0 is parametrized by its Minkowski content measure such that γ (0) = 0, then it is a 1 /d -self similar process defined on R with stationary increments, i.e., ( γ ( at )) ∼ ( a 1 /d γ ( t )) , ∀ a > 0; ( γ ( a + t ) − γ ( a )) ∼ ( γ ( t )) , ∀ a ∈ R . 26 / 39

  61. H¨ older continuity and dimension theorem We want to study the H¨ older continuity and dimension properties of γ . The problem boils down to the finiteness of momentums of | γ (1) | : Lemma For any c ∈ ( − d, ∞ ) , E [ | γ (1) | c ] < ∞ . 27 / 39

  62. H¨ older continuity and dimension theorem We want to study the H¨ older continuity and dimension properties of γ . The problem boils down to the finiteness of momentums of | γ (1) | : Lemma For any c ∈ ( − d, ∞ ) , E [ | γ (1) | c ] < ∞ . Following the parallel argument on Brownian motion, we obtain 27 / 39

  63. H¨ older continuity and dimension theorem We want to study the H¨ older continuity and dimension properties of γ . The problem boils down to the finiteness of momentums of | γ (1) | : Lemma For any c ∈ ( − d, ∞ ) , E [ | γ (1) | c ] < ∞ . Following the parallel argument on Brownian motion, we obtain Theorem (H¨ older Continuity) γ is locally α -H¨ older continuous for any α < 1 /d . 27 / 39

  64. H¨ older continuity and dimension theorem We want to study the H¨ older continuity and dimension properties of γ . The problem boils down to the finiteness of momentums of | γ (1) | : Lemma For any c ∈ ( − d, ∞ ) , E [ | γ (1) | c ] < ∞ . Following the parallel argument on Brownian motion, we obtain Theorem (H¨ older Continuity) γ is locally α -H¨ older continuous for any α < 1 /d . Theorem (Mckean’s Dimension Theorem) For any deterministic closed set A ⊂ R , a.s. dim( γ ( A )) = d · dim( A ) . 27 / 39

  65. Unrooted loop We use rooted SLE κ loop measures to construct unrooted SLE κ loop measure in � C . It is a σ -finite measure on unrooted loops. An unrooted loop is a continuous function defined on the circle S 1 , modulo an orientation-preserving auto-homeomorphism of S 1 . We may view the two-sided whole-plane SLE κ measure ν # z ⇋ w as a measure on unrooted loops. By the work of Miller and Sheffield, a two-sided whole-plane SLE κ satisfies reversibility, i.e., we have ν # z ⇋ w = ν # w ⇋ z as measures on unrooted loops. 28 / 39

  66. Unrooted loop Theorem Define the measure µ 0 on unrooted loops by � � µ 0 = Cont( · ) − 2 · ν # z ⇋ w | w − z | − 2(2 − d ) A ( dw ) A ( dz ) . C C Then µ 0 is a σ -finite measure that satisfies: 29 / 39

  67. Unrooted loop Theorem Define the measure µ 0 on unrooted loops by � � µ 0 = Cont( · ) − 2 · ν # z ⇋ w | w − z | − 2(2 − d ) A ( dw ) A ( dz ) . C C Then µ 0 is a σ -finite measure that satisfies: (i) the decomposition formulas: z ( dγ ) ← − µ 0 ( dγ ) ⊗ M γ ( dz ) = µ 1 ⊗ A ( dz ); z ⇋ w ( dγ ) ← − µ 0 ( dγ ) ⊗ ( M γ ) 2 ( dz ⊗ dw ) = ν # ⊗| w − z | − 2(2 − d ) · ( A ) 2 ( dz ⊗ dw ) . obius invariance: W ( µ 0 ) = µ 0 . (ii) M¨ 29 / 39

  68. SLE loops in subdomains of � C For SLE loops in subdomains of � C , we follow Lawler’s approach. 30 / 39

  69. SLE loops in subdomains of � C For SLE loops in subdomains of � C , we follow Lawler’s approach. Let L D ( V 1 , V 2 ) = { loops in D that intersect both V 1 and V 2 } . Let c = (6 − κ )(3 κ − 8) . Recall µ lp is the Brownian loop measure. 2 κ 30 / 39

  70. SLE loops in subdomains of � C For SLE loops in subdomains of � C , we follow Lawler’s approach. Let L D ( V 1 , V 2 ) = { loops in D that intersect both V 1 and V 2 } . Let c = (6 − κ )(3 κ − 8) . Recall µ lp is the Brownian loop measure. 2 κ Let U be a multiply connected domain with two boundary points a, b on the same boundary component. We may find a simply connected domain D ⊃ U such that ∂D is the component of ∂U containing a, b . Lawler defined the SLE κ in U from a to b as U ; a → b = 1 {·⊂ U } e c µ lp ( L D ( · ,U c )) · µ # µ D D ; a → b . 30 / 39

  71. SLE loops in subdomains of � C For SLE loops in subdomains of � C , we follow Lawler’s approach. Let L D ( V 1 , V 2 ) = { loops in D that intersect both V 1 and V 2 } . Let c = (6 − κ )(3 κ − 8) . Recall µ lp is the Brownian loop measure. 2 κ Let U be a multiply connected domain with two boundary points a, b on the same boundary component. We may find a simply connected domain D ⊃ U such that ∂D is the component of ∂U containing a, b . Lawler defined the SLE κ in U from a to b as U ; a → b = 1 {·⊂ U } e c µ lp ( L D ( · ,U c )) · µ # µ D D ; a → b . Conformal covariance: if U j ⊂ D j , a j , b j ∈ ∂U j , j = 1 , 2, and Conf f : ( U 1 ; a 1 , b 1 ) ։ ( U 2 ; a 2 , b 2 ), then 6 − κ 6 − κ f ( µ D U 1 ; a 1 → b 1 ) = | f ′ ( a 1 ) | 2 κ | f ′ ( b 1 ) | 2 κ µ D U 2 ; a 2 → b 2 . If µ D U ; a → b is finite, we may normalize it to get a probability measure with conformal invariance. 30 / 39

  72. SLE loops in subdomains of C For D ⊂ � C , we wanted to define C ( · ,D c )) · µ 1 C ( · ,D c )) · µ 0 . D ; z = 1 {·⊂ D } e c µ lp ( L � D = 1 {·⊂ D } e c µ lp ( L � µ 1 µ 0 z , 31 / 39

  73. SLE loops in subdomains of C For D ⊂ � C , we wanted to define C ( · ,D c )) · µ 1 C ( · ,D c )) · µ 0 . D ; z = 1 {·⊂ D } e c µ lp ( L � D = 1 {·⊂ D } e c µ lp ( L � µ 1 µ 0 z , However, µ lp ( L ( γ, D c )) is not finite for any curve γ in D . The correct alternative is the normalized Brownian loop measure introduced in [Field-Lawler], i.e., r ↓ 0 [ µ lp Λ ∗ ( V 1 , V 2 ) := lim {| z − z 0 | >r } ( L ( V 1 , V 2 )) − log log(1 /r )] , 31 / 39

  74. SLE loops in subdomains of C For D ⊂ � C , we wanted to define C ( · ,D c )) · µ 1 C ( · ,D c )) · µ 0 . D ; z = 1 {·⊂ D } e c µ lp ( L � D = 1 {·⊂ D } e c µ lp ( L � µ 1 µ 0 z , However, µ lp ( L ( γ, D c )) is not finite for any curve γ in D . The correct alternative is the normalized Brownian loop measure introduced in [Field-Lawler], i.e., r ↓ 0 [ µ lp Λ ∗ ( V 1 , V 2 ) := lim {| z − z 0 | >r } ( L ( V 1 , V 2 )) − log log(1 /r )] , The limit converges if V 1 and V 2 are disjoint compact subsets of � C ; and the value does not depend on the z 0 ∈ � C . 31 / 39

  75. SLE loops in subdomains of C For D ⊂ � C , we wanted to define C ( · ,D c )) · µ 1 C ( · ,D c )) · µ 0 . D ; z = 1 {·⊂ D } e c µ lp ( L � D = 1 {·⊂ D } e c µ lp ( L � µ 1 µ 0 z , However, µ lp ( L ( γ, D c )) is not finite for any curve γ in D . The correct alternative is the normalized Brownian loop measure introduced in [Field-Lawler], i.e., r ↓ 0 [ µ lp Λ ∗ ( V 1 , V 2 ) := lim {| z − z 0 | >r } ( L ( V 1 , V 2 )) − log log(1 /r )] , The limit converges if V 1 and V 2 are disjoint compact subsets of � C ; and the value does not depend on the z 0 ∈ � C . The correct way to define SLE κ loop measures in D ⊂ � C is using Λ ∗ ( · , D c ) in place of µ lp ( L � C ( · , D c )). 31 / 39

  76. SLE loops in subdomains of � C Theorem The µ 1 D ; z and µ 0 D defined using normalized Brownian loop measure satisfy conformal covariance and conformal invariance, respectively: if Conf W : U ։ V , and z ∈ U , then W ( µ 1 U ; z ) = | W ′ ( z ) | 2 − d µ 1 V ; W ( z ) ; W ( µ 0 U ) = µ 0 V . 32 / 39

  77. SLE loops in subdomains of � C Theorem The µ 1 D ; z and µ 0 D defined using normalized Brownian loop measure satisfy conformal covariance and conformal invariance, respectively: if Conf W : U ։ V , and z ∈ U , then W ( µ 1 U ; z ) = | W ′ ( z ) | 2 − d µ 1 V ; W ( z ) ; W ( µ 0 U ) = µ 0 V . The proof uses CMP of rooted SLE κ loop in � C and the generalized restriction property of chordal SLE κ . 32 / 39

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