arXiv subjects

Yosuke Imamura

Publications and source records attributed to Yosuke Imamura.

At least 19 recordsLinked to original sources

arXiv2026

Line operator indices of S-fold theories

We study superconformal indices in the presence of line operators in S-fold theories. We consider two types of lines, realized by fundamental strings and fivebranes, respectively, in AdS$_5 \times S^5/\mathbb{Z}_k$. For fundamental lines, we analyze the corresponding indices including finite-$N$ corrections arising from giant graviton configurations. For $k=2$, we compare the holographic results with line operator indices in $\mathcal{N}=4$ super Yang-Mills theories with orthogonal gauge groups. For $k=3,4$ and $6$, we focus on the rank $2$ case, in which the supersymmetry is enhanced to ${\cal N}=4$, and compare them with the corresponding Wilson-'t Hooft line operator indices. In both cases, we find improved agreement once giant graviton contributions are included. For line operators realized by fivebranes, after confirming agreement for $k=2$, we construct BPS configurations for $k\geq 3$ explicitly using fivebrane junctions and derive the indices in the large $N$ limit by the mode analysis on the fivebrane junctions.

hep-th↗

arXiv2025

D1-brane correction to a line operator index

Wilson line operators in the rank $k$ totally symmetric tensor representation of ${\cal N}=4$ $U(N)$ sypersymmetric Yang-Mills theories are expected to be realized as D3-branes expanded in $AdS_5$. Although there is a mismatch between the corresponding line operator indices even in the large $N$ and large $k$ limit, it is possible to calculate the finite $k$ correction on the AdS side as the contribution from D1-branes. We analyze D1-brane fluctuation modes and calculate the leading finite $k$ correction to the line operator index on the AdS side.

hep-th↗

arXiv2024

Giant graviton expansion for general Wilson line operator indices

We propose a giant graviton expansion for Wilson line operator indices in general representations. The inserted line operators are specified by power sum symmetric polynomials $p_\lambda$ labeled by partitions $\lambda$. We interpret the partitions as the structure of fundamental string worldsheets wrapping around the temporal circle. The strings may or may not end on giant gravitons, and by summing the contributions from all brane configurations consistent with the specified partitions, we obtain the finite $N$ line operator index. The proposed formula is consistent with known results and passes highly non-trivial numerical tests.

hep-th↗

arXiv2024

Inductive calculation of superconformal indices based on giant graviton expansion

We investigate a simple-sum giant graviton expansion of the superconformal indices of ${\cal N}=2$ superconformal field theories realized on D3-branes probing $7$-brane backgrounds with constant axio-dilation field. The expansion is of self-dual type, and imposes strong constraints on the indices. By using the constraints we determine first few terms in the superconformal indices for arbitrary rank $N$.

hep-th↗

arXiv2024

Brane expansions for anti-symmetric line operator index

Based on the D5-brane realization of Wilson line operators in anti-symmetric representations, we propose brane expansion formulas for $I_{N,k}$, the Schur index of ${\cal N}=4$ $U(N)$ SYM decorated by line operators in the anti-symmetric representation of rank $k$. For the large $N$ index $I_{\infty,k}$ we propose a double-sum expansion, and for finite $N$ index $I_{N,k}$ we propose a quadruple-sum expansion. Objects causing finite $k$ and finite $N$ corrections are disk D3-branes ending on the D5-brane.

hep-th↗

arXiv2024

Giant graviton expansions for line operator index

We discuss giant graviton expansions for the Schur index of ${\cal N}=4$ $U(N)$ SYM with the insertion of Wilson lines of the fundamental and the anti-fundamental representations. We first propose a double-sum giant graviton expansion and numerically confirm that it correctly reproduces the line-operator index. We also find that it reduces to a simple-sum expansion when we treat the index as a Taylor series with respect to a specific fugacity.

hep-th↗

arXiv2023

Simple-Sum Giant Graviton Expansions for Orbifolds and Orientifolds

We study giant graviton expansions of the superconformal index of 4d orbifold/orientifold theories. In general, a giant graviton expansion is given as a multiple sum over wrapping numbers. It has been known that the expansion can be reduced to a simple sum for the ${\cal N}=4$ $U(N)$ SYM by choosing appropriate expansion variables. We find such a reduction occurs for a few examples of orbifold and orientifold theories: $\mathbb{Z}_k$ orbifold and orientifolds with $O3$ and $O7$. We also argue that for a quiver gauge theory associated with a toric Calabi-Yau $3$-fold the simple-sum expansion works only if the toric diagram is a triangle, that is, the Calabi-Yau is an orbifold of $\mathbb{C}^3$.

hep-th↗

arXiv2023

A Stringy Effect on Hawking Radiation

In string theories, interactions are exponentially suppressed for trans-Planckian space-like external momenta. We study a class of quantum field theories that exhibit this feature modeled after Witten's bosonic open string field theory, and discover a Lorentz-invariant UV/IR relation that leads to the spacetime uncertainty principle proposed by Yoneya. Application to a dynamical black hole background suggests that Hawking radiation is turned off around the scrambling time.

hep-th↗

arXiv2022

Analytic continuation for giant gravitons

We investigate contributions of giant gravitons to the superconformal index. We concentrate on coincident giant gravitons wrapped around a single cycle, and each contribution is obtained by a certain variable change for fugacities from the index of the worldvolume theory on the giant gravitons. Because we treat the index as a series of fugacities and the variable change relates different convergence regions, we need an analytic continuation before summing up such contributions. We propose a systematic prescription for the continuation. Although our argument is based on some unproved assumptions, it passes non-trivial numerical checks for some examples. With the prescription we can calculate the indices of the M5-brane theories from those of the M2-brane theories, and vice versa.

hep-th↗

arXiv2021

Holographic index calculation for Argyres-Douglas and Minahan-Nemeschansky theories

We calculate the superconformal indices of the $\mathcal N=2$ superconformal field theories realized on $N$ coincident D3-branes in 7-brane backgrounds with constant axiodilaton via the AdS/CFT correspondence. We include the finite-$N$ corrections as the contribution of D3-branes wrapped around 3-cycles in the internal space. We take only single-wrapping contributions into account for simplicity. We also determine the orders of the next-to-leading corrections which we do not calculate. The orders are relatively high, and we obtain many trustable terms. We give the results for $N=1,2,3$ explicitly, and find nice agreement with known results.

hep-th↗

arXiv2021

Finite-$N$ superconformal index via the AdS/CFT correspondence

We propose a prescription to calculate the superconformal index of the ${\cal N}=4$ $U(N)$ supersymmetric Yang-Mills theory with finite $N$ on the AdS side. The finite $N$ corrections are included as contributions of D3-branes wrapped around three-cycles in $\boldsymbol{S}^5$, which are calculated as the index of the gauge theories realized on the wrapped branes. The single-wrapping contribution has been studied in a previous work, and we further confirm that the inclusion of multiple-wrapping contributions correctly reproduces the higher order terms as far as we have checked numerically.

hep-th↗

arXiv2021

Flavor symmetries of six-dimensional ${\cal N}=(1,0)$ theories from AdS/CFT correspondence

We calculate the superconformal indices of a class of six-dimensional ${\cal N}=(1,0)$ superconformal field theories realized on M5-branes at $\mathbb{C}^2/\mathbb{Z}_k$ singularity by using the method developed in previous works of the authors and collaborators. We use the AdS/CFT correspondence, and finite $N$ corrections are included as the contribution of M2-branes wrapped on two-cycles in $S^4/\mathbb{Z}_k$. We confirm that the indices are consistent with the expected flavor symmetries.

hep-th↗

arXiv2020

Finite-$N$ corrections to the M-brane indices

We investigate finite-$N$ corrections to the superconformal indices of the theories realized on M2- and M5-branes. For three-dimensional theories realized on a stack of $N$ M2-branes we calculate the finite-$N$ corrections as the contribution of extended M5-branes in the dual geometry $AdS_4\times \boldsymbol{S}^7$. We take only M5-brane configurations with a single wrapping into account, and neglect multiple-wrapping configurations. We compare the results with the indices calculated from the ABJM theory, and find agreement up to expected errors due to the multiple wrapping. For six-dimensional theories on $N$ M5-branes we calculate the indices by analyzing extended M2-branes in $AdS_7\times \boldsymbol{S}^4$. Again, we include only configurations with single wrapping. We first compare the result for $N=1$ with the index of the free tensor multiplet to estimate the order of the error due to multiple wrapping. We calculate first few terms of the index of $A_{N-1}$ theories explicitly, and confirm that they can be expanded by superconformal representations. We also discuss multiple-wrapping contributions to the six-dimensional Schur-like index.

hep-th↗

arXiv2020

Schur index of the ${\cal N}=4$ $U(N)$ SYM via the AdS/CFT correspondence

We calculate the Schur index of the ${\cal N}=4$ $U(N)$ SYM with finite $N$ via the AdS/CFT correspondence as the contribution of D3-branes wrapped on contractible cycles in $\boldsymbol{S}^5$ on some assumptions motivated by preliminary analyses. As far as we have checked numerically it agrees with the index calculated on the gauge theory side. In a certain limit it reproduces the analytic result given by Bourdier, Drukker, and Felix.

hep-th↗

arXiv2019

Finite $N$ corrections to the superconformal index of toric quiver gauge theories

The superconformal index of quiver gauge theories realized on D3-branes in toric Calabi-Yau cones is investigated. We use the AdS/CFT correspondence and study D3-branes wrapped on supersymmetric cycles. We focus on brane configurations in which a single D3-brane is wrapped on a cycle, and we do not take account of branes with multiple wrapping. We propose a formula that gives finite $N$ corrections to the index caused by such brane configurations. We compare the predictions of the formula for several examples with the results on the gauge theory side obtained by using localization for small size of gauge groups, and confirm that the formula correctly reproduces the finite $N$ corrections up to expected order.

hep-th↗

arXiv2019

Finite $N$ corrections to the superconformal index of orbifold quiver gauge theories

We investigate the AdS/CFT correspondence for quiver gauge theories realized on D3-branes put on abelian orbifolds by using the superconformal index. We assume that on the gravity side the finite $N$ corrections of the index are reproduced by D3-branes wrapped on three particular three-cycles in the internal space ${\cal Y}$, the abelian orbifold of $\boldsymbol{S}^5$. We first establish the relation between baryonic charges on the gauge theory side and the D3-brane wrapping numbers and holonomies on D3-branes. Then we confirm our proposal by comparing the results of localization for gauge theories and the results on the AdS side including the contributions of D3-branes and excitation on them for many examples. We only focus on the leading finite $N$ corrections starting from $q^N$, and leave the sub-leading corrections starting at $q^{kN}$ ($k\geq2$) as a task for the future. We find complete agreement for the leading corrections in all examples.

hep-th↗

arXiv2019

Finite $N$ Corrections to the Superconformal Index of S-fold Theories

We study the superconformal index of S-fold theories by using AdS/CFT correspondence. It has been known that the index in the large $N$ limit is reproduced as the contribution of bulk Kaluza-Klein modes. For finite $N$ D3-branes wrapped around the non-trivial cycle in $\boldsymbol{S}^5/\mathbb{Z}_k$, which corresponds to Pfaffian-like operators, give the corrections of order $q^N$ to the index. We calculate the finite $N$ corrections by analyzing the fluctuations of wrapped D3-branes. Comparisons to known results show that our formula correctly reproduces the corrections up to errors of order $q^{2N}$.

hep-th↗

arXiv2019

BPS Partition Functions for S-folds

We derive a formula for the BPS partition functions of arbitrary S-fold theories. We first generalize the known result for the ${\cal N}=4$ $U(N)$ supersymmetric Yang-Mills theory to $SO$ and $Sp$ theories, and then we extend the formula to ${\cal N}=3$ theories. We confirm that the results for rank $1$ and $2$ are consistent to the supersymmetry enhancement from ${\cal N}=3$ to ${\cal N}=4$. We also derive the same formula from the quantization of D3-branes in $\boldsymbol{S}^5/\mathbb{Z}_k$.

hep-th↗