arXiv subjects

Yi Pang

Publications and source records attributed to Yi Pang.

At least 19 recordsLinked to original sources

arXiv2026

BMPV black holes in higher-derivative supergravity

There are five independent four-derivative superinvariants for the five-dimensional STU model, of which two are vector invariants that do not involve curvature tensors. We construct the corrected BMPV black hole directly in five dimensions with this set of general four-derivative couplings, a computation made possible with the help of AI. We find that the vector invariants do not correct the solution or the entropy, while the entropy associated with the heterotic corrections agrees with recent results.

hep-th↗

arXiv2026

Diagonally gauged anomaly-free 6D supergravities and their vacua

We describe a bounded search for local and global anomaly-free six-dimensional $(1,0)$ models with tensor number $T=1$ and gauge group containing a diagonal abelian factor $U(1)_{R+}$. The abelian factor is the diagonal combination of the usual gauged $U(1)_R$ and a $U(1)\subset Sp(n_H)$ acting on hypermultiplets. We have searched for locally and globally anomaly-free $G_1\times U(1)_{R+}$ and $G_1\times G_2\times U(1)_{R+}$ models, subject to restrictions on the ranks of the simple factors and on the maximal charges carried by matter. We find that, unlike the case of $U(1)_R$ gauged models which are relatively rare, the diagonally gauged ones offer a rich landscape. We also study the 6D vacua of these models and find that they admit supersymmetric 6D Minkowski vacua, for which the diagonal nature of the R-symmetry gauging is necessary.

hep-th↗

arXiv2026

What U Can Do: New Solutions and New Challenges Beyond Leading Order

String theories naturally exhibit dualities that lead to hidden symmetries in the low-energy effective description, which have been used to great effect to generate supergravity solutions. We review recent progress in using hidden symmetries arising from T-duality to generate higher-derivative-corrected solutions, as well as the problems that arise from non-perturbative effects when extending this paradigm to hidden symmetries arising from U-duality.

hep-th↗

arXiv2026

Symmetries of non-maximal supergravities with higher-derivative corrections

We consider hidden symmetries arising from U-duality in the dimensional reduction of non-maximal higher-derivative supergravities to three dimensions. In particular, we consider the $G_{2(2)}$ symmetry of minimal five-dimensional supergravity and the $O(d+p+1,d+1)$ symmetry of bosonic and heterotic string theory on $T^d$. Using a group theory argument, we show that the higher-derivative corrections explicitly break all hidden symmetry enhancements. As special cases, this also implies that higher-derivative corrections prevent the symmetry enhancement to $SL(3,\mathbb R)$ in pure five-dimensional gravity and $O(4,4)$ in the STU model.

hep-th↗

arXiv2026

$S^3$ partition functions and Equivariant CY$_4 $/CY$_3$ correspondence from Quantum curves

We study the perturbative large-$N$ expansion of the round three-sphere partition function in a class of M2-brane theories, including flavored SYM and ABJM theories as well as more general 3d theories admitting dual $(p,q)$ 5-brane web descriptions. Using the Fermi gas formalism and quantum curve techniques, we derive the Airy-function representation of the partition function and find exact agreement with predictions based on equivariant constant maps in topological string theory proposed in [1]. In particular, we provide affirmative tests of this proposal for the toric geometries $\mathbb{C} \times \mathcal{C}$ (the conifold), the cone over the Sasakian space $Q^{1,1,1}$, and $\mathbb{C} \times \mathrm{SPP}$ (the suspended pinch point). Motivated by a recent conjecture in [2], we further propose a novel equivariant correspondence between distinct toric Calabi-Yau manifolds of the form $\mathrm{CY}_4 \leftrightarrow \mathbb{C} \times\mathrm{CY}_3$, arising from relations between the corresponding quantum curves under specific constraints. This correspondence suggests an equivariant extension and points toward a geometric origin of the topological string/spectral theory (TS/ST) correspondence, while offering new insight into the structure of the holographic duality.

hep-th↗

arXiv2026

New $F^4$ invariants in five-dimensional supergravity

We consider four-derivative superinvariants of five-dimensional $\mathcal N=2$ supergravity coupled to $n_v\le 2$ vector multiplets, which we obtain from both the superconformal tensor calculus approach and dimensional reduction. For the minimal case, with no vector multiplets, it is known that there is a unique four-derivative superinvariant. However, for the case of one vector multiplet, after field redefinitions, we find that there are three independent superinvariants, one of which is a vector superinvariant that does not contain any curvatures and takes the form of a supersymmetrization of $F^4$. Similarly, for the two vector multiplet case, corresponding to the STU model, we find three gravitational superinvariants and two $F^4$-type vector superinvariants. Moreover, we find that these vector superinvariants do not affect the two- and three-charge static BPS black hole solutions. We further consider the rigid limit to $\mathcal N=2$ super-Yang-Mills and use this to conjecture a family of vector superinvariants for five-dimensional $\mathcal N=2$ supergravity coupled to an arbitrary number of vector multiplets.

hep-th↗

arXiv2025

Holographic origin of $a$-maximization and higher-derivative AdS$_5$/CFT$_4$

We develop a consistent partially off-shell framework for evaluating higher-derivative actions of five-dimensional $\cal{N}=1$ gauged supergravity with abelian vector multiplets on AdS$_5$. Using the superconformal formalism, we show that the resulting holographic expression reproduces the trial $a$-anomaly coefficient of the dual conformal field theory, identifying the supergravity equations of motion with $a$-maximization. We present an exact correspondence between Chern-Simons couplings and the anomaly polynomial of the boundary theory. We illustrate our proposal by applying it to all known two- and four-derivative actions, including the ``off-diagonal'' invariants never before considered in the gauged supergravity literature. Finally, we argue that all invariants beyond four-derivative yield no genuinely new contributions to asymptotically AdS$_5$ BPS backgrounds, but instead reduce to linear combinations of the established two- and four-derivative actions.

hep-th↗

arXiv2025

Full spectrum of Love numbers of Reissner-Nordstrom black hole in D-dimensions

We present a comprehensive analysis of the full spectrum of tidal Love numbers for Reissner-Nordstr\"om (RN) black holes in general spacetime dimensions. By perturbing the Einstein-Maxwell theory around the $D$-dimensional RN background, we derive an effective two dimensional quadratic action encompassing tensor, vector, and scalar-type perturbation sectors. Through diagonalization, we obtain master equations governing each sector and extract the corresponding Love numbers from the asymptotic behavior of the solutions. Our results confirm that all Love numbers vanish for four-dimensional RN black holes. In higher dimensions, the tensor and vector Love numbers reproduce previously known results. For the previously unknown scalar-type Love numbers, we show also they vanish for integer valued effective multipolar indices and display logarithmic running behavior when the corresponding indices are half integers.

hep-th↗

arXiv2025

4D de Sitter from 6D gauged supergravity with Green-Schwarz counterterm

Taking into account the Green-Schwarz anomaly counterterm in R-symmetry gauged $N=(1,0)$ supergravity in six dimensions, and the associated modification in the Maxwell kinetic term and potential, the theory admits half-supersymmetric Mink$_4\times S^2$ and non-supersymmetric dS$_4 \times S^2$ solutions with or without a monopole on $S^2$. The monopole charge and the anomaly coefficients play key roles in the vacuum structure and a diagonal gauging in which an admixture of an external $U(1)$ with the R-symmetry $U(1)_R$ is needed for the de Sitter solutions to exist. We determine the full Kaluza-Klein spectrum for both vacua. The spectrum is unitary in the Minkowski case but in the case of de Sitter vacuum, the dilaton and the breathing mode are tachyonic. We show that turning on small perturbations of the tachyonic modes around dS$_4\times S^2$ with a monopole on $S^2$ triggers a flow evolving towards Mink$_4\times S^2$ with the minimal potential energy. The diagonally gauged model also supports dS$_2\times S^4$ solution which avoids tachyons for certain values of the flux on dS$_2$. We also find nonsupersymmetric (A)dS$_4\times S^2$ solutions, when we turn on a flux associated with external $U(1)$ gauge field only, and show that they support the phenomenon of scale separation under certain conditions on anomaly coefficients.

hep-th↗

arXiv2025

Consistent Four-derivative Heterotic Truncations and the Kerr-Sen Solution

Four-derivative heterotic supergravity (without gauge fields) reduced on a $p$-dimensional torus leads to half-maximal supergravity coupled to $p$ vector multiplets, and it is known that removing the vector multiplets is a consistent truncation of the theory. We find a new consistent truncation of four-derivative heterotic supergravity on a torus that keeps the vector multiplets and precisely reproduces the bosonic action of heterotic supergravity (with heterotic gauge fields). We show that both truncations have an $O(d+p,d)$ symmetry when reduced on a $d$-dimensional torus and demonstrate how this embeds in the $O(d+p,d+p)$ symmetry that one gets from reducing on a $(d+p)$-dimensional torus without truncation. We then use our new truncation to obtain four-derivative corrections to the Kerr-Sen solution and compute thermodynamic quantities and multipole moments. Finally, we compare the Kerr-Sen solutions of the actions corresponding to the two different choices of truncation with the Kerr solution, the Kerr-Newman solution, and each other, and show that they have distinct four-derivative multipole structures.

hep-th↗

arXiv2025

Constraining Cubic Curvature Corrections to General Relativity with Quasi-Periodic Oscillations

We investigate observational constraints on cubic curvature corrections to general relativity by analyzing quasi-periodic oscillations (QPOs) in accreting black hole systems. In particular, we study Kerr black hole solution corrected by cubic curvature terms parameterized by $\beta_5$ and $\beta_6$. While $\beta_6$ corresponds to a field-redefinition invariant structure, the $\beta_5$ term can in principle be removed via a field redefinition. Nonetheless, since we work in the frame where the accreting matter minimally couples to the metric, $\beta_5$ is in general present. Utilizing the corrected metric, we compute the QPO frequencies within the relativistic precession framework. Using observational data from GRO J1655$-$40 and a Bayesian analysis, we constrain the coupling parameters to $-12.31<\frac{\beta_5}{(5 M_\odot)^4}<24.15$ and $-1.99<\frac{\beta_6}{(5 M_\odot)^4}<0.30$ at 2-$\sigma$. These bounds improve upon existing constraints from big-bang nucleosynthesis and the speed of gravitational waves.

gr-qc↗

arXiv2025

Higher-derivative Heterotic Kerr-Sen Black Holes

We obtain the four-derivative corrections to the Kerr-Sen solution in heterotic supergravity, which includes the Gibbons-Maeda-Garfinkle-Horowitz-Strominger solution as a limiting case. In particular, we first embed the Kerr solution into heterotic supergravity and compute the higher-derivative corrections. We then obtain the corrections to the Kerr-Sen solution by performing an $O(2,1)$ boost of the Kerr solution, which, in contrast to the two-derivative case, requires field redefinitions to make the $O(2,1)$ invariance of the action manifest. Finally, we compute the multipole moments and find that they are distinct from those of the Kerr solution at the four-derivative level. We also find that the multipole moments are distinct from those of the Kerr-Newman solution in Einstein-Maxwell theory at the four-derivative level, even for the most general choice of four-derivative corrections. This gives a way to experimentally distinguish traces of string theory in gravitational wave data.

hep-th↗

arXiv2025

Black hole thermodynamics at 4 derivatives, natural variables and BPS limits

We study Einstein-Maxwell theory in $D \geq 3$ spacetime dimensions including all Lorentz-invariant parity-even four-derivative couplings. Building on the results of arXiv:2312.11610, we consider static, charged, asymptotically flat black hole solutions to first order in the higher-derivative expansion. In $D=4$ and $D=5$, we compute the corrected black hole thermodynamics and compare with the Reall-Santos prescription based on the two-derivative background, highlighting a subtlety when both inner and outer horizons are involved. By introducing natural variables, as in arXiv:2304.07320, we recast the on-shell actions in terms of left- and right-moving chemical potentials, which significantly simplifies the analysis. We also compute first-order thermodynamic corrections for the most general rotating black holes in $D=4$ and $D=5$, without modifying the background solutions. We identify a novel BPS-like limit in $D=4$, extending known supergravity results beyond their traditional domain of validity. Finally, in $D=5$, the analysis of BPS and almost BPS limits enables an independent verification of the five-dimensional BPS thermodynamics. We clarify the origin of a discrepancy in the literature concerning higher-derivative supergravity localization, sharpening the tension between direct computations and predictions based on the $D=4$/$D=5$ connection.

hep-th↗

arXiv2025

On five-dimensional curvature squared supergravity and holography

In this work, we report the recent progress in obtaining new curvature-squared invariants in 5D, N=1 gauged minimal supergravity. We exhibit the structure of various composite multiplets that are pivotal in the construction. We also present the form of the gauged Riemann-squared and Gauss-Bonnet superinvariants in a dilaton-Weyl multiplet. As a first application of the new curvature squared invariants, we compute their corrections to holographic central charges and the Euclidean action of supersymmetric charged rotating black holes, exhibiting exact matching between the gravity and CFT results.

hep-th↗

arXiv2025

Exact large $N$ expansion of $\mathcal{N}=4$ circular quiver Chern-Simons theories and squashing

In this work, we revisit the exact computation of the round sphere partition function of 3d $\mathcal{N}=4$ circular quiver Chern-Simons theories with mass and Fayet-Iliopoulos (FI) deformations. Utilizing the Fermi gas formalism, we derive the large $N$ expansion of the partition function and determine the Airy function structure, parameterized by three functions $C$, $B$ and $A$. We propose a novel closed-form expression for $A$ that incorporates the effects of FI parameters and satisfies various consistency constraints from quiver reductions. As an application, by using an accidental coincidence of the Fermi gas density matrices we extend our results to the squashed sphere partition function of $\mathcal{N}=4$ super Yang-Mills theories with an adjoint hypermultiplet and multiple fundamental hypermultiplets. Our findings provide further evidence for the universality of the Airy function structure in supersymmetric gauge theories of multiple M2-branes.

hep-th↗

arXiv2025

Inequality of opportunity under current China's license plate policy

Measuring inequality of opportunities has long been a challenging and open problem, primarily due to the limitations associated with individual-level data. In this study, we utilize data obtained from vehicle license plates in a comprehensive survey (17258 vehicles from 6 major cities in China) to evaluate the inequality of opportunities in the country. In our context, we define inequality of opportunity as the scenario where relatively expensive vehicles have a higher likelihood of being paired with license plates featuring 'Lucky Numbers'. To quantify this, we propose a lucky-number-based opportunity Gini coefficient. Through the calculation of the opportunity Gini coefficient, we observe a significant and positive correlation between opportunity inequality and income inequality. Particularly noteworthy is our finding that the advancement of technology, exemplified by the widespread adoption of new energy vehicles, can substantially reduce the inequality of opportunity. Taking incorporation of a random lottery process before acquiring a motor vehicle in Beijing and Shanghai as a natural experiment, our empirical results support the argument that, in terms of equality, employing random drawing is a fair and equitable approach for allocating scarce resources.

econ.GN↗

arXiv2024

Leading Higher Derivative Corrections to Multipole Moments of Kerr-Newman Black Hole

We study the (leading) 4-derivative corrections, including both parity even and odd terms, to electrically-charged Kerr-Newman black holes. The linear perturbative equations are then solved order by order in terms of two dimensionless rotating and charge parameters. The solution allows us to extract the multipole moments of mass and current from the metric as well as the electric and magnetic multipole moments from the Maxwell field. We find that all the multipole moments are invariant under the field redefinition, indicating they are well-defined physical observables in this effective theory approach to quantum gravity. We also find that parity-odd corrections can turn on the multipole moments that vanish in Einstein theory, which may have significant observational implications.

hep-th↗

arXiv2024

Exact large $N$ expansion of mass deformed ABJM theory on squashed sphere

In this paper we study the partition function of the mass deformed ABJM theory on a squashed three sphere. In particular, we focus on the case with the Chern-Simons levels being $\pm 1$ and apply a duality between this theory and the $\mathcal{N}=4$ $\mathrm{U}\left(N\right)$ super Yang-Mills theory with an adjoint hypermultiplet and a fundamental hypermultiplet. For a special mass parameter depending on the squashing parameter, we find that the partition function can be written as that of an ideal Fermi gas with a non-trivial density matrix. By studying this density matrix, we analytically derive the all order perturbative expansion of the partition function in $1/N$, which turns out to take the form of the Airy function. Our results not only align with previous findings and conjectures but also lead to a new formula for the overall constant factor of the partition function. We also study the exact values of the partition function for small but finite values of $N$.

hep-th↗