arXiv subjects

Ji-Seong Chae

Publications and source records attributed to Ji-Seong Chae.

4 recordsLinked to original sources

arXiv2026

Perturbative Nicolai-Map Diagrammatics: Application to Poincaré Supergravity

We develop a perturbative, diagrammatic framework for constructing Nicolai maps and apply it to four-dimensional $\mathcal{N}=1$ Poincaré supergravity expanded around flat Minkowski space. It provides an alternative to the coupling-flow-operator construction, which faces several obstructions when extended to local supersymmetry. Expanding the bosonic effective action and the Nicolai map jointly in the gravitational coupling $κ$ and the loop-counting parameter $\hbar$, we derive the Nicolai-map defining conditions, i.e. the free-action and determinant-matching conditions, order by order. The diagrammatics enumerates all admissible local terms in the Nicolai-map ansatz from the effective-action diagrams and reduces the construction to a finite system of nonlinear polynomial equations. Carried through order $κ^{2}$, the resulting constraints are found to be independent of the detailed bosonic input and hierarchical, order-$κ^{2}$ consistency further restricting the order-$κ$ data. A consistent Nicolai-map construction for the Einstein--Hilbert graviton sector is found to require the Rarita--Schwinger gravitino already at this order: Einstein gravity admits a Nicolai map only through its $\mathcal{N}=1$ supersymmetric completion, Poincaré supergravity, supporting Nicolai's characterization of supersymmetry.

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arXiv2026

Exact Finite-$N$ eRS Surface-Defect Indices and Giant-Graviton Corrections in $\mathcal N=4$ SYM

We compute the exact finite-$N$ superconformal index of four-dimensional $\mathcal N=4$ $U(N)$ Yang--Mills theory with antisymmetric elliptic Ruijsenaars--Schneider (eRS) surface-defect insertions. By matching the inserted eRS Hamiltonians to their independent realization in five-dimensional $\mathcal N=1^*$ gauge theory, we interpret that the solvable locus $t=q$ corresponds to vanishing adjoint mass. Motivated by this massless specialization, we impose the four-dimensional balancing condition $p=uv$. At this point, the eRS operators are conjugate to free $q$-shifts, and the self-glued matrix integral reduces to a bilateral free-fermion determinant. This gives closed finite-$N$ formulas for every antisymmetric rank. On $v=0$, we determine the stable pure $u^{kN}$ corrections at all wrapping orders; the bilateral formula also captures the reflected $v^{kN}$ sectors and mixed $u$--$v$ contributions. We further formulate the balanced perturbation away from $t=q$ through second order in terms of connected correlators. Finally, a maximal-D3 determinant reproduces the ordinary one-giant coefficient and isolates the microscopic input required for the defect correction.

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arXiv2026

Covariant Holographic Entanglement Entropy Inversion to Reconstruct Bulk Geometry

We derive an analytic inverse map from the renormalized covariant interval entropy to a symmetry-reduced stationary bulk metric. The main result applies to stationary homogeneous asymptotically AdS$_3$ geometries with a radial lapse, an independent spatial warp factor, and a stationary shift. On a smooth HRT branch, the interval entropy $S_{\ren}(Δt,Δx)$ is an on-shell Hamilton--Jacobi functional. Its endpoint derivatives determine two conserved charges, and the ratio $κ=E/J$ organizes the extremal curves into one-parameter families with varying bulk turning points. For each fixed $κ$, the length and endpoint-separation data give three Volterra equations with the standard Abel square-root kernel. Their inverse kernels reconstruct the radial coordinate and the metric functions $f,h,v$. We also state the local consistency conditions and the agreement required when two local reconstructions of the same smooth HRT family cover an overlapping radial interval. The construction is verified in pure AdS, rotating BTZ, a static warped geometry, and an Einstein--scalar black brane, and extended to higher-dimensional strips when the transverse area density is fixed by symmetry.

hep-th↗

arXiv2026

Holographic Entanglement Anisotropy as a Dark Deformation RG Probe in Hyperscaling-Violating $p$-Wave Superfluids

We study dark-sector deformations of anisotropic $p$-wave superfluids in hyperscaling-violating black-brane backgrounds, where the visible non-Abelian sector condenses a vector order parameter that breaks boundary spatial rotations and supplies a directional entanglement probe. Reading the strip entanglement entropy as a function of width turns this probe into a scale-resolved diagnostic: in four and five bulk dimensions, the orientation difference $S_\perp-S_\parallel$ separates hidden couplings into scale-independent and width-running classes while filtering out isotropic dark sources entirely. Hidden-current mixing renormalizes the visible anisotropic response by a width-independent factor and strongly hybridizes the critical vector mode; a scalar gauge-kinetic portal instead reweights the radial Yang--Mills operator, so Ryu--Takayanagi surfaces of different widths sample different depths of the bulk deformation. We treat this scalar channel as a sourced boundary-value problem with a dilaton-dressed mass term, yielding a controlled short-width power law. The channel classification, the sign of each response, and the short-width exponent $2Δ_{\rm UV}$ are fixed by the background weights and the ultraviolet scalar falloff; the running-channel amplitude is not, since it depends on the portal normalization. We therefore state our conclusions at the level of these normalization-independent discriminants. The three-dimensional case is treated separately as an interval response.

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