arXiv:1905.05522 · SciPost Physics Core

Entanglement entropy from entanglement contour: higher dimensions

Muxin Han, Qiang Wen

Published Apr 12, 2022• 32 citations

Abstract

We study the entanglement contour and partial entanglement entropy (PEE) in quantum field theories in 3 and higher dimensions. The entanglement entropy is evaluated from a certain limit of the PEE with a geometric regulator. In the context of the entanglement contour, we classify the geometric regulators, study their difference from the UV regulators. Furthermore, for spherical regions in conformal field theories (CFTs) we find the exact relation between the UV and geometric cutoff, which clarifies some subtle points in the previous literature. We clarify a subtle point of the additive linear combination (ALC) proposal for PEE in higher dimensions. The subset entanglement entropies in the ALC proposal should all be evaluated as a limit of the PEE while excluding a fixed class of local-short-distance correlation. Unlike the 2-dimensional configurations, naively plugging the entanglement entropy calculated with a UV cutoff will spoil the validity of the ALC proposal. We derive the entanglement contour function for spherical regions, annuli and spherical shells in the vacuum state of general-dimensional CFTs on a hyperplane.

DOI: 10.21468/scipostphyscore.5.2.020

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arXiv:1905.05522 · SciPost Physics Core

Entanglement entropy from entanglement contour: higher dimensions

Muxin Han, Qiang Wen

Published Apr 12, 2022• 32 citations

arXiv HTML PDF

Abstract

DOI: 10.21468/scipostphyscore.5.2.020

Related papers

Entanglement entropies from entanglement contour: annuli and spherical shells

Muxin Han, Qiang Wen

The partial entanglement entropy $s_{\mathcal{A}}(\mathcal{A}_i)$ captures the contribution from the subset $\mathcal{A}_i$ of the region $\mathcal{A}$ to the total entanglement entropy $S_{\mathcal{A}}$ of $\mathcal{A}$ . The partial entanglement entropy proposal \cite{Wen:2018whg,Wen:2019ubu} claims that $s_{\mathcal{A}}(\mathcal{A}_i)$ equals to a linear combination of the entanglement entropies of certain relevant subsets in $\mathcal{A}$ . We derive the differential version of this proposal which can directly generate the scheme independent entanglement contour function. Furthermore we derived the sufficient condition to apply the differential version of proposal. On the other way around, the proposal indicates that given the partial entanglement entropy we can calculate the entanglement entropies for the subsets. Following this idea, on the field theory side we analytically calculated the entanglement contour functions and entanglement entropies for annuli and spherical shells in holographic CFTs in arbitrary dimensions. We also comment on the phase transition of the mutual information, which is calculated holographically, across an annulus.The partial entanglement entropy $s_{\mathcal{A}}(\mathcal{A}_i)$ captures the contribution from the subset $\mathcal{A}_i$ of the region $\mathcal{A}$ to the total entanglement entropy $S_{\mathcal{A}}$ of $\mathcal{A}$. The partial entanglement entropy proposal \cite{Wen:2018whg,Wen:2019ubu} claims that $s_{\mathcal{A}}(\mathcal{A}_i)$ equals to a linear combination of the entanglement entropies of certain relevant subsets in $\mathcal{A}$. We derive the differential version of this proposal which can directly generate the scheme independent entanglement contour function. Furthermore we derived the sufficient condition to apply the differential version of proposal. On the other way around, the proposal indicates that given the partial entanglement entropy we can calculate the entanglement entropies for the subsets. Following this idea, on the field theory side we analytically calculated the entanglement contour functions and entanglement entropies for annuli and spherical shells in holographic CFTs in arbitrary dimensions. We also comment on the phase transition of the mutual information, which is calculated holographically, across an annulus.

May 14, 201913 citations

Entanglement contour and modular flow from subset entanglement entropies

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Abstract The Entanglement contour function quantifies the contribution from each degree of freedom in a region $\mathcal{A}$ A to the entanglement entropy ${S}_{\mathcal{A}}$ S A . Recently in [1] the author gave two proposals for the entanglement contour in two-dimensional theories. The first proposal is a fine structure analysis of the entanglement wedge, which applies to holographic theories. The second proposal is a claim that for general two-dimensional theories the partial entanglement entropy is given by a linear combination of entanglement entropies of relevant subsets inside $\mathcal{A}$ A . In this paper, we further study the partial entanglement entropy proposal by showing that it satisfies all the rational requirements proposed previously. We also extend the fine structure analysis from vacuum AdS space to BTZ black holes. Furthermore, we give a simple prescription to generate the local modular flows for two-dimensional theories from only the entanglement entropies without refer to the explicit Rindler transformations.Abstract The Entanglement contour function quantifies the contribution from each degree of freedom in a region $$ \mathcal{A} $$ A to the entanglement entropy $$ {S}_{\mathcal{A}} $$ S A . Recently in [1] the author gave two proposals for the entanglement contour in two-dimensional theories. The first proposal is a fine structure analysis of the entanglement wedge, which applies to holographic theories. The second proposal is a claim that for general two-dimensional theories the partial entanglement entropy is given by a linear combination of entanglement entropies of relevant subsets inside $$ \mathcal{A} $$ A . In this paper, we further study the partial entanglement entropy proposal by showing that it satisfies all the rational requirements proposed previously. We also extend the fine structure analysis from vacuum AdS space to BTZ black holes. Furthermore, we give a simple prescription to generate the local modular flows for two-dimensional theories from only the entanglement entropies without refer to the explicit Rindler transformations.

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Pablo Bueno, Adam Fernández García, Francesco Gentile +2 more

A bstract The entanglement entropy of spacetime regions A in odd-dimensional conformal field theories (CFTs) contains a universal constant term, ${\left(-1\right)}^{\frac{d-1}{2}}\ F(A)$ − 1 d − 1 2 F A . This quantity can be robustly defined by considering the mutual information of pairs of slightly deformed versions of A . In the case of general three-dimensional CFTs, F ( A ) is positive definite and bounded below by the round disk result, F ( A ) ≥ F 0 ≡ F ( ∂A = 𝕊 1 ). Additionally, strong evidence has been provided that for every region A , F ( A ) /F 0 is maximized, within the space of CFT 3 ’s, by the free scalar field result. In this paper we show that while F ( A ) remains a local minimum around F 0 ≡ F ( ∂A = 𝕊 3 ) for small deformations of the spherical entangling surface, it can take values of arbitrarily large magnitude with either sign for more general regions, and hence it is neither upper- nor lower-bounded in general CFT 5 ’s. We argue that an analogous conjecture regarding the extremization of F ( A ) /F 0 for general regions within the space of theories fails in d = 5. We instead analyze the viability of the weaker bound, F ϵ /F 0 ≤ F ϵ /F 0 | free scalar , ∀CFT 5 for general small geometric deformations of the spherical entangling surface. This is equivalent to a general constraint involving the stress-tensor two-point function C T and the Euclidean partition function on the sphere, namely, C T /F 0 ≤ C T /F 0 | free scalar ≈ 0 . 314, which we show to hold for all known CFT 5 ’s. We also comment on possible extensions of this result to higher dimensions.A bstract The entanglement entropy of spacetime regions A in odd-dimensional conformal field theories (CFTs) contains a universal constant term, $$ {\left(-1\right)}^{\frac{d-1}{2}}\ F(A) $$ − 1 d − 1 2 F A . This quantity can be robustly defined by considering the mutual information of pairs of slightly deformed versions of A . In the case of general three-dimensional CFTs, F ( A ) is positive definite and bounded below by the round disk result, F ( A ) ≥ F 0 ≡ F ( ∂A = 𝕊 1 ). Additionally, strong evidence has been provided that for every region A , F ( A ) /F 0 is maximized, within the space of CFT 3 ’s, by the free scalar field result. In this paper we show that while F ( A ) remains a local minimum around F 0 ≡ F ( ∂A = 𝕊 3 ) for small deformations of the spherical entangling surface, it can take values of arbitrarily large magnitude with either sign for more general regions, and hence it is neither upper- nor lower-bounded in general CFT 5 ’s. We argue that an analogous conjecture regarding the extremization of F ( A ) /F 0 for general regions within the space of theories fails in d = 5. We instead analyze the viability of the weaker bound, F ϵ /F 0 ≤ F ϵ /F 0 | free scalar , ∀CFT 5 for general small geometric deformations of the spherical entangling surface. This is equivalent to a general constraint involving the stress-tensor two-point function C T and the Euclidean partition function on the sphere, namely, C T /F 0 ≤ C T /F 0 | free scalar ≈ 0 . 314, which we show to hold for all known CFT 5 ’s. We also comment on possible extensions of this result to higher dimensions.

arXiv:2604.01436Journal of High Energy PhysicsAug 17, 20260 citations

Geometrizing the partial entanglement entropy: from PEE threads to bit threads

Jiong Lin, Yizhou Lu, Qiang Wen

A bstract We give a scheme to geometrize the partial entanglement entropy (PEE) for holographic CFT in the context of AdS/CFT. More explicitly, given a point x we geometrize the two-point PEEs between x and any other points in terms of the bulk geodesics connecting these two points. We refer to these geodesics as the PEE threads , which can be naturally regarded as the integral curves of a divergenceless vector field ${V}_{\textbf{x}}^{\mu }$ V x μ , which we call PEE thread flow . The norm of ${V}_{\textbf{x}}^{\mu }$ V x μ that characterizes the density of the PEE threads can be determined by some physical requirements of the PEE. We show that, for any static interval or spherical region A , a unique bit thread configuration can be generated from the PEE thread configuration determined by the state. Hence, the non-intrinsic bit threads are emergent from the intrinsic PEE threads. For static disconnected intervals, the vector fields describing a divergenceless flow is no longer suitable to reproduce the RT formula. We weight a PEE thread with the number of times it intersects with any homologous surface. Instead, the RT formula is perfectly reformulated by the minimization of the summation of PEE threads with all possible assignment of weights.A bstract We give a scheme to geometrize the partial entanglement entropy (PEE) for holographic CFT in the context of AdS/CFT. More explicitly, given a point x we geometrize the two-point PEEs between x and any other points in terms of the bulk geodesics connecting these two points. We refer to these geodesics as the PEE threads , which can be naturally regarded as the integral curves of a divergenceless vector field $$ {V}_{\textbf{x}}^{\mu } $$ V x μ , which we call PEE thread flow . The norm of $$ {V}_{\textbf{x}}^{\mu } $$ V x μ that characterizes the density of the PEE threads can be determined by some physical requirements of the PEE. We show that, for any static interval or spherical region A , a unique bit thread configuration can be generated from the PEE thread configuration determined by the state. Hence, the non-intrinsic bit threads are emergent from the intrinsic PEE threads. For static disconnected intervals, the vector fields describing a divergenceless flow is no longer suitable to reproduce the RT formula. We weight a PEE thread with the number of times it intersects with any homologous surface. Instead, the RT formula is perfectly reformulated by the minimization of the summation of PEE threads with all possible assignment of weights.

arXiv:2311.02301Journal of High Energy PhysicsFeb 23, 202413 citations

The partial entanglement entropy

s_{\mathcal{A}}(\mathcal{A}_i)

captures the contribution from the subset

\mathcal{A}_i

of the region

\mathcal{A}

to the total entanglement entropy

S_{\mathcal{A}}

\mathcal{A}

. The partial entanglement entropy proposal \cite{Wen:2018whg,Wen:2019ubu} claims that

s_{\mathcal{A}}(\mathcal{A}_i)

equals to a linear combination of the entanglement entropies of certain relevant subsets in

\mathcal{A}

. We derive the differential version of this proposal which can directly generate the scheme independent entanglement contour function. Furthermore we derived the sufficient condition to apply the differential version of proposal. On the other way around, the proposal indicates that given the partial entanglement entropy we can calculate the entanglement entropies for the subsets. Following this idea, on the field theory side we analytically calculated the entanglement contour functions and entanglement entropies for annuli and spherical shells in holographic CFTs in arbitrary dimensions. We also comment on the phase transition of the mutual information, which is calculated holographically, across an annulus.

Abstract The Entanglement contour function quantifies the contribution from each degree of freedom in a region

\mathcal{A}

A to the entanglement entropy

{S}_{\mathcal{A}}

S A . Recently in [1] the author gave two proposals for the entanglement contour in two-dimensional theories. The first proposal is a fine structure analysis of the entanglement wedge, which applies to holographic theories. The second proposal is a claim that for general two-dimensional theories the partial entanglement entropy is given by a linear combination of entanglement entropies of relevant subsets inside

\mathcal{A}

A . In this paper, we further study the partial entanglement entropy proposal by showing that it satisfies all the rational requirements proposed previously. We also extend the fine structure analysis from vacuum AdS space to BTZ black holes. Furthermore, we give a simple prescription to generate the local modular flows for two-dimensional theories from only the entanglement entropies without refer to the explicit Rindler transformations.

Entanglement contour characterizes the spatial structure of entanglement and quantifies the contribution from the degrees of freedom in any subset of the region

\mathcal{A}

to the total entanglement entropy

S_{\mathcal{A}}

. Recently in \cite{Wen:2018whg} the author gave a simple proposal for the entanglement contour (or partial entanglement entropy) in two-dimensional theories, which involves the entanglement entropies of all the subsets inside

\mathcal{A}

. In this paper we explicitly study this proposal and show it satisfies many rational requirements for entanglement contour. Together with the holographic picture constructed with the modular planes \cite{Wen:2018whg}, we propose the correspondence between bulk geodesic chords and boundary partial entanglement entropies, which can be considered as a finer version of the Ryu-Takayanagi (RT) formula. As an example we calculate the fine correspondence between the points on

\mathcal{A}

and the points on the RT surface

\mathcal{E}_{\mathcal{A}}

for the BTZ black hole. We also give a strategy to extract the local modular flow from our proposal.

A bstract The entanglement entropy of spacetime regions A in odd-dimensional conformal field theories (CFTs) contains a universal constant term,

{\left(-1\right)}^{\frac{d-1}{2}}\ F(A)

− 1 d − 1 2 F A . This quantity can be robustly defined by considering the mutual information of pairs of slightly deformed versions of A . In the case of general three-dimensional CFTs, F ( A ) is positive definite and bounded below by the round disk result, F ( A ) ≥ F 0 ≡ F ( ∂A = 𝕊 1 ). Additionally, strong evidence has been provided that for every region A , F ( A ) /F 0 is maximized, within the space of CFT 3 ’s, by the free scalar field result. In this paper we show that while F ( A ) remains a local minimum around F 0 ≡ F ( ∂A = 𝕊 3 ) for small deformations of the spherical entangling surface, it can take values of arbitrarily large magnitude with either sign for more general regions, and hence it is neither upper- nor lower-bounded in general CFT 5 ’s. We argue that an analogous conjecture regarding the extremization of F ( A ) /F 0 for general regions within the space of theories fails in d = 5. We instead analyze the viability of the weaker bound, F ϵ /F 0 ≤ F ϵ /F 0 | free scalar , ∀CFT 5 for general small geometric deformations of the spherical entangling surface. This is equivalent to a general constraint involving the stress-tensor two-point function C T and the Euclidean partition function on the sphere, namely, C T /F 0 ≤ C T /F 0 | free scalar ≈ 0 . 314, which we show to hold for all known CFT 5 ’s. We also comment on possible extensions of this result to higher dimensions.

{V}_{\textbf{x}}^{\mu }

V x μ , which we call PEE thread flow . The norm of

{V}_{\textbf{x}}^{\mu }

V x μ that characterizes the density of the PEE threads can be determined by some physical requirements of the PEE. We show that, for any static interval or spherical region A , a unique bit thread configuration can be generated from the PEE thread configuration determined by the state. Hence, the non-intrinsic bit threads are emergent from the intrinsic PEE threads. For static disconnected intervals, the vector fields describing a divergenceless flow is no longer suitable to reproduce the RT formula. We weight a PEE thread with the number of times it intersects with any homologous surface. Instead, the RT formula is perfectly reformulated by the minimization of the summation of PEE threads with all possible assignment of weights.