Papers

Wormholes are a hypothetical object that connects disparate points in spacetime. It is a theoretically well-motivated black hole alternative and offers a potential observationally testable arena for probing strong-field gravity with horizon-scale images. We perform general relativistic magnetohydrodynamic (GRMHD) simulations and general relativistic radiative transfer (GRRT) calculations of accretion flows onto a Kerr-like wormhole. Adopting a Kerr black-bounce metric with a fixed throat parameter $\ell = 2.5\,\rm M$, we explore the effects of spin using both two- and three-dimensional simulations. The accretion flow is initialized as a magnetized geometrically thick torus near one mouth of the wormhole, while the opposite mouth is initially gas-free. We find that the spin parameter influences the dynamical properties on both sides of the wormhole through the frame-dragging effects. Based on the GRMHD results, we compute ray-traced images at $230\,\mathrm{GHz}$ using RAPTOR, and analyze the horizon-scale image structure through higher-order photon trajectories. Our GRRT calculations show that emissions originating from the immediate vicinity of the throat can dominate, in contrast to the case of a Kerr black hole. It provides the variable component of the signal and imprints a clear quasi-periodic modulation in the light curves. These properties would be useful to either confirm or rule out such exotic compact objects through horizon-scale observations.

We study the singlet-sector structure of mass-deformed BFSS$_{d+1}$ matrix quantum mechanics by combining the large–\(d\) Gaussian reduction with the Molien–Weyl projection. The Gaussian reduction captures the bulk matrix dynamics through a gauged harmonic oscillator, while the Molien–Weyl integral imposes the Gauss law and reorganizes the physical Hilbert space into holonomy-projected singlet excitations. We show that the very-low-temperature bosonic singlet spectrum is universally controlled by the quadratic Gram operators \(\Tr(X_aX_b)\), whose number is \(d(d+1)/2\). For \(N=2\), this result is established by explicit residue computations and character methods; for \(N>2\), it is supported by the character analysis. Thus the infrared spectrum begins as a collection of BFSS$_2$–like Gram towers, although higher invariant structures generally modify the full partition function. We also give a Hamiltonian derivation of the exceptional exact factorization at \((d,N)=(2,2)\), where the BFSS$_3$ singlet partition function equals the cube of the BFSS$_2$ one for all temperatures. This rigidity is special to the \(SU(2)\) invariant tensor structure and explains why \(d=1\) and \(N=2\) are exceptional regimes without a deconfinement crossover. Finally, we extend the Gram-counting picture to supersymmetric BFSS/BMN models and indicate how the Molien–Weyl formulation can benchmark Monte Carlo simulations in both \(X_a\)-space and holonomy space.

We apply the dictionary of gauge-gravity dualities to study the spectrum of bound states in a special one-parameter family of strongly coupled, confining field theories in four dimensions. The top-down, holographic gravity dual description of this class of theories has been identified recently. It consists of non-supersymmetric regular background solutions of Romans half-maximal supergravity theory in six dimensions, in the presence of a non-trivial Abelian magnetic flux along a compactified direction of the geometry. A zero-temperature, deconfinement, first-order phase transition appears at one end of this branch of solutions. It is triggered by the strength of the flux, setting an upper bound on the magnitude of the magnetic flux that can be supported by the geometry. We compute the spectrum of fluctuations of the background fields in the gravity description, that correspond to field-theory bound states. Two scalar particles are the lightest in the spectrum, their masses being suppressed and almost degenerate across the whole parameter space. Away from the transition, the heaviest between these two particles is identified as a dilaton, the pseudo-Nambu-Goldstone boson associated with scale invariance. It couples to the trace of the stress-energy tensor of the dual field theory, while the lightest scalar does not. In the range of parameter space closest to the extremum of the one-parameter family, near the first-order phase transition, a region with large curvature appears at the end of space of the geometry of the solutions. In this range, the two scalars mix non-trivially, and their masses are parametrically suppressed, in respect to the other bound states.

Chaotic many-body dynamics typically generates volume-law entanglement from initially low-entangled states. We reveal an intricate, hierarchical entanglement structure in local quantum quenches, both in the canonical purification of locally quenched Gibbs states and in a companion pure-state circuit model. In either setting, the full state exhibits a Renyi-index-tuned transition: at long times, $S_{\alpha>1}$ obeys an area law, while $S_{\alpha\le 1}$ is volume-law. More strikingly, the response linear in the quench strength is carried by only an O(1)-dimensional dominant Schmidt sector; the corresponding states exhibit their own area-to-volume-law transitions at critical indices $\alpha_c<1$, implying polynomial-bond-dimension approximability in one dimension. We provide evidence that this hierarchy persists recursively: upon bipartitioning the dominant Schmidt states, their leading Schmidt sectors exhibit analogous structure. We derive the mechanism analytically in the circuit model, prove the $S_{\alpha>1}$ area law for locally quenched Gibbs states, and support the hierarchy by exact diagonalization of random circuits and locally quenched Gibbs states of chaotic spin chains.

We introduce a new family of cosmological attractors with non-minimal coupling of gravity and non-canonical kinetic terms. In the Einstein frame, these models transform into a class of exponential and polynomial attractors with the spectral index $n_{s}$ spanning a broad range $1-2/N \leq n_{s} < 1-1/N$, and $r$ can decrease to zero in the limit $\xi \to \infty$. This is sufficient to match any combination of Planck, BICEP/Keck, ACT, SPT, and DESI data. We present a supergravity implementation of these models.

This dissertation presents a unified framework for medium characterization with hard probes spanning from Cherenkov light in quantum electrodynamics (QED) to jet drift in quantum chromodynamics (QCD). We first develop a dispersive fit to the refractive index $n(\lambda)$ of liquid argon (LAr) by incorporating anomalous dispersion at the 106.6 nm resonance for the first time. We show that the angular distribution of Cherenkov radiation is highly sensitive to the peak of the refractive index and contributes a significant excess over isotropic scintillation in certain angular bins. This work is important for precision Particle Identification (PID) for experiments like DUNE and CCM. Transitioning to high-energy nuclear collisions, we utilize “jet drift” – the flow-induced deflection of partons – as a tomographic probe of the Quark-Gluon Plasma (QGP). Using the Anisotropic Parton Evolution (APE) Monte Carlo simulation across various collision systems (PbPb, AuAu, and UU), we disentangle how the jet modification depends on medium size, temperature, and geometry. We show that jet drift exhibits distinct systematics in observables like the elliptic flow ($v_2$) and dihadron acoplanarity ($\Delta\phi$), which helps disentangle it from conventional energy loss. Together, these studies demonstrate how the angular and kinematic signatures of hard probes revolutionize our ability to resolve the fundamental properties of matter.

Spontaneous CP violation (SCPV) provides a promising solution to the strong CP problem, explaining the smallness of the QCD $\theta$-angle while generating the Cabibbo-Kobayashi-Maskawa (CKM) phase. In the present work, we review and discuss the realization of SCPV in the supersymmetric framework, which addresses critical issues such as the naturalness of the scale of SCPV and the presence of problematic higher dimensional operators and radiative corrections spoiling the mechanism. It is explicitly shown that SCPV is realized along flat directions and stabilized through supersymmetry-breaking effects and a non-perturbative dynamics, predicting light SCPV sector particles feebly coupled to the Standard Model particles. Furthermore, we discuss the issue of baryon asymmetric Universe in the SCPV framework and point out that the Affleck-Dine mechanism can successfully generate the observed baryon asymmetry with a low reheating temperature compatible with the gravitino dark matter. Our framework predicts a nonzero neutron electric dipole moment which is within the reach of near-future experiments.

Zimmermann's Reduction of Couplings (RoC) method is a powerful tool for addressing the problem of the excess of parameters in a field theory, as it yields relations among couplings that are invariant under the renormalization group. Its usefulness becomes particularly evident when constructing predictive supersymmetric GUT models that are free of UV-divergences to all orders. Within this scale-invariant framework, we show that a SUSY model satisfying the conditions of all-loop finiteness exhibits a conformal regime induced by superpotential operators compatible with the RoC. In the soft-breaking sector, the method was shown to lead to a set of scale-invariant relations between the soft couplings and the parameters of the dimensionless sector, among which a sum rule for the scalar masses is particularly notable. These relations closely resemble the typical AMSB relations, while avoiding the tachyonic mass spectrum thanks to the sum rule. Based on this observation, we provide new evidence for a connection between the reduction of parameters in the dimensionful SSB sector and the emergence of an anomaly-mediated (AMSB-like) pattern, under the assumption that the finite Grand Unified Theory is connected to an effective $N=1$, $d=4$ Weyl-invariant SUGRA theory. In this process, we find that an all-order finite model with this property requires a specific form of the Kähler potential, whose structure coincides with that studied in no-scale supergravity scenarios.

The collapse of supermassive stars (SMSs, $M\gtrsim10^4\,M_\odot$) to black holes is accompanied by a prodigious flux of neutrinos of all flavors. These are produced thermally via $e^\pm$ annihilations, mostly in the core and just before gravitational trapped surface formation. There, the ratio of fluxes for $\nu_e\bar{\nu}_e$-pairs to $\nu_{\mu}\bar{\nu}_{\mu}/\nu_{\tau}\bar{\nu}_{\tau}$-pairs is $\sim$\,5-to-1. This is because at SMS temperature scales, $\nu_e\bar{\nu}_e$ pairs have both charged and neutral current production channels, whereas $\nu_{\mu}\bar{\nu}_{\mu}/\nu_{\tau}\bar{\nu}_{\tau}$-pairs only have neutral current production channels. We point out that the typical energies of these neutrinos, and the run of density in collapsing radiation-dominated supermassive configurations, leads to Mikheyev-Smirnov-Wolfenstein (MSW) resonances inside these objects for the atmospheric neutrino mass splitting scale, $\Delta m^2_\mathrm{atm.}\sim2.4\times10^{-3}$ eV$^2$. In the normal neutrino mass hierarchy, adiabatic flavor transformation through the MSW resonances would then swap the fluxes $\nu_e\leftrightharpoons\nu_{\mu,\tau}$, whereas, in the inverted neutrino mass hierarchy, the anti-neutrino fluxes are swapped, $\bar{\nu}_e\leftrightharpoons\bar{\nu}_{\mu,\tau}$. We also examine the prospects for collective neutrino flavor oscillations in these environments. Implications for flavor oscillation's effects on neutrino energy deposition and neutrino-induced nucleosynthesis in the SMS's outer layers are examined, as are prospects for detections of SMS collapses through various means.

For an infalling circular string, we study particle production, Krylov complexity, Lanczos coefficients, and operator growth induced by quantum fluctuations. Using canonical quantization in the squeezed state formalism, we show that significant particle production arises only in the radial sector as the string approaches the black hole horizon, while angular modes remain weakly excited. Exploiting the equivalence between particle number and Krylov complexity for two mode states, we find that nontrivial complexity scaling emerges only in the near-horizon, effectively thermalized regime, where the state approaches a thermofield double form. In this limit, the particle number exhibits a polynomial dependence on the initial position of the probe string. We further identify a linear dependence of the operator growth rate on the initial position of the probe string, suggesting a universal scaling behavior of operator growth and providing support for the complexity volume correspondence.

The study of hyperbolic binary black hole encounters yields an effective probe of the strong field regime of black holes, thus providing an additional channel to test General Relativity. We study the scattering of two black holes in Einstein-scalar-Gauss-Bonnet gravity, a well-motivated effective field theory of gravity, by comparing the scattering angle obtained from the first fully nonlinear black hole scattering simulations with its effective-one-body analytic description. We obtain excellent agreement between analytics and numerics, exhibiting accurate capturing of strong-field scalar-gravitational dynamics. Our work paves the way towards semi-analytical waveform templates of compact object binaries in modified theories of gravity.

We analyze the emergence of nonlocal magic in Schwinger pair creation in strong non-Abelian (chromo)electric fields using holography. The produced quark–antiquark pair is entangled into a color singlet, yet accelerates into causally disconnected Rindler wedges. Using the Casini–Huerta–Myers conformal mapping and the probe-brane framework, we compute the refined Rényi entropy and its derivative, which captures the antiflatness of the entanglement spectrum for a spherical bipartition. We find that for boundary spacetime dimension $d>2$, the entanglement spectrum is non-flat, implying the dynamical generation of nonlocal magic in the pair creation process. Interestingly, the nonlocal magic in the holographic dual can be obtained from the free energy of the probe action.

The pressure-energy equations of state in the nucleon are derived from the gravitational form factors, which parametrize matrix elements of the energy-momentum tensor (EMT), together with EMT conservation. The pressure and energy densities naturally separate into two distinct components. The static pressure distribution, arising from the Lorentz trace part of the EMT, as manifested in the spatial stress $\frac{1}{3} T^{ii}$, is equal to minus the corresponding trace part of the energy density. This relation may be interpreted as a consequence of the full or partial depletion of the gluon and quark condensates through the pressure-volume relation. The resulting trace anomaly- and sigma term-induced pressure is shown, through its volume scaling, to play a pivotal role in QCD confinement. In contrast, the dynamic pressure distribution, associated with the traceless part of the stress tensor equals $1/d$ of the corresponding traceless part of the energy density, where $d$ is the spatial dimension. These static and dynamic components together satisfy the pressure-balance condition in the nucleon. We further show that the same pressure-energy equations of state hold for vortices in type-II superconductors, where the static pressure-energy relation originates from the depletion of the Cooper-pair condensate. Moreover, these equations of state are identical to those of the $\Lambda{\rm CDM}$ cosmological model, where the static pressure-energy relation is generated by the cosmological constant.

I study constraints on fundamental physics emerging from consistency of a unitary, local and perturbative $S$-matrix in $4d$. For massless particles, some new constraints arising from consistent complex factorisation of $2\rightarrow 2$ amplitudes are derived, leading, in particular, to the complete structure of the gluon three-particle amplitudes, including the geometric restrictions on the Lie algebra, parity and time-reversal symmetry, among other details. For massive particles, a hierarchy of constraints may be derived instead by imposing a maximum rate of unitarity-violating growth in the high energy limit. All $2\rightarrow 2$ tree-level amplitudes of massive particles with spin $s\leq 1$ are calculated in generality using on-shell methods and presented with manifest high energy dependence. The anatomy of these amplitudes' helicity sectors is dissected in order to identify conditions under which their energy growth is limited or eliminated. Using these results, it is shown that the scattering of massive vector bosons has suppressed, but not fully unitarised, high energy dependence if the parity-conserving parts of their self-couplings are Lie algebra structure constants, possibly non-semisimple or non-compact, and the parity-violating parts are “generalised Chern-Simons terms”. Full unitarisation then requires the standard Yang-Mills Lie algebra properties and, for a gapped spectrum, the Higgs mechanism. These amplitudes are assembled, embedded and unified into elegant superamplitudes in theories with extended supersymmetry when the particles are BPS. More generally, a broader landscape of EFTs is charted through various combinations of constraints and coupling hierarchies.

We study heterotic Calabi–Yau compactifications with NSNS three-form flux in view of moduli stabilisation and investigate whether the value $|W_0|$ of the flux superpotential evaluated at supersymmetric minima can be small. Unlike in type IIB string theory, heterotic compactifications lack a no-scale structure, so that a non-vanishing flux superpotential generically induces a tree-level scalar potential for all moduli. Controlled moduli stabilisation therefore requires the flux superpotential to be sufficiently small in order to compete with non-perturbative effects. Working within a four-dimensional effective field theory and exploiting the special geometry of Calabi–Yau complex structure moduli spaces, we analyse the complex structure F-term equations and derive two no-go theorems: (1) supersymmetric vacua with vanishing $|W_0|$, which would lead to a vanishing tree-level scalar potential as in type IIB, occur only at singular loci in moduli space, and (2) no supersymmetric vacua with small $|W_0|$ exist in the large complex structure limit. Motivated by these results, we analyse explicit models away from the large complex structure regime using exact period expressions and identify one- and two-parameter examples in which suitable flux choices allow for values of $|W_0|$ of order unity, with some one-parameter models admitting values moderately below unity. Our findings show that small heterotic flux superpotentials are highly constrained, with the values of $|W_0|$ found in the examples studied being only marginally compatible with moduli stabilisation.

We develop a formulation of perturbation theory on spherically symmetric backgrounds based on self-dual curvature equations combined with spherical harmonic expansions. The resulting framework unifies the Regge-Wheeler-Zerilli (RWZ) and Bardeen-Press-Teukolsky (BPT) formalisms and is designed to combine key advantages of both. The use of self-dual variables is crucial, and makes quasinormal mode isospectrality manifest, when present. We present the formalism first for a general energy-momentum tensor, and then specialize to vacuum General Relativity with matter sources to illustrate its practical advantages. A central result is that the RWZ and BPT equations arise directly as different components of a single tensorial curvature equation. We also show that, in the frequency domain, the metric can be reconstructed algebraically from any of the proposed master functions and their derivatives, and we comment on possible obstructions to such a reconstruction in the time domain. A Mathematica notebook, based on xAct, that implements the formalism and was used in our computations is released alongside this work.

We discuss low-energy effective theories with a Dirac gravitino. Our main benchmark is Scherk–Schwarz supersymmetry breaking with anti-periodic boundary conditions for fermions on S^1/Z_2. In this case two Majorana spin-3/2 modes are degenerate, so the low-energy theory is naturally organized around a Dirac gravitino and an associated R-symmetry selection rule. We show, in minimal supergravity, that this Dirac spin-3/2 mixing has no local Dirac-gaugino-type N=1 superspace realization: a superspace description requires projection onto the transverse superspin-3/2 sector. We then analyze some consequences for matter couplings and radiative masses. The ordinary gravitino supercurrent coupling gives the standard universal Scherk–Schwarz scalar threshold; in the minimal benchmark this contribution is negative, and should therefore be regarded as one calculable contribution to the scalar mass matrix, not as a complete scalar-spectrum prediction. Dirac fermion masses can be generated if an additional companion-channel matter current is present. The existence and normalization of this current are not fixed by the Dirac gravitino alone and depend on the ultraviolet completion. We finally discuss small R-breaking deformations, the resulting pseudo-Dirac regime, and comment on possible applications to singlet fermions, modulini, and radiative Dirac neutrino masses.

We analyse three-dimensional Einstein gravity coupled to a massive complex scalar field with double-trace boundary conditions. Using high-precision spectral methods, we construct regular AdS$_3$ boson stars together with axisymmetric and non-axisymmetric hairy black holes. For each azimuthal number $m$, the hairy black holes bifurcate from the BTZ family at the corresponding double-trace instability onset. When the double-trace parameter satisfies $\kappa < \kappa_{\rm AdS}$, global AdS$_3$ becomes unstable and we identify its nonlinear endpoint as a zero-frequency boson star with energy below that of AdS$_3$, thereby providing the true ground state of the theory. In the microcanonical ensemble, hairy black holes always carry greater entropy than BTZ at fixed mass and angular momentum, and thus dominate whenever they exist. With notable exceptions, typically hairy black holes do not dominate the canonical nor the grand-canonical ensembles. We further show that, in the singular extremal limit, axisymmetric black holes saturate a generalised minimum-energy theorem under double-trace boundary conditions. These results yield the full nonlinear phase diagram of AdS$_3$ gravity with double-trace deformations.

We show that in heterotic string theory – and dual corners of the landscape including Type I string theory – the QCD axion mass is bounded from below by $m_a \gtrsim 0.5$ neV, a direct consequence of the model-independent axion whose decay constant is fixed by the grand unified theory (GUT) gauge coupling. We explicitly compute the mass of the QCD axion in an ensemble of heterotic compactifications on Calabi-Yau hypersurfaces of toric varieties sampled from the Kreuzer-Skarke (KS) ensemble, as well as on complete intersection Calabi-Yau manifolds. We then perform an extensive search over the Kähler moduli space of KS compactifications with up to $11$ axions – the maximum we identify as consistent with unification in our sample. We establish that for all but a handful of manifolds the QCD axion mass is precisely the model-independent value, lying in $[0.5, 0.8]$ neV, depending on the GUT gauge coupling. This window should be a high-priority target for future lumped-element detectors such as DMRadio-GUT. We show that the heavy axion population in our heterotic ensemble generically decays before big bang nucleosynthesis and can naturally accommodate leptogenesis, unlike in Type IIB axiverse constructions.

We construct new classes of supersymmetric $AdS_2\times \Sigma$ solutions, where $\Sigma=\Sigma(n_N,n_S)$ is a spindle. Such solutions can arise as the near horizon limit of supersymmetric, accelerating black holes. The solutions are constructed using $D=4$ STU $U(1)^4$ gauged supergravity theory coupled to a charged hyperscalar, and can be uplifted to obtain smooth, supersymmetric $AdS_2\times Y_9$ solutions of $D=11$ supergravity. We allow $(n_N,n_S)$ to be non-coprime integers, including orbifolds of the round $S^2$. We also allow the hyperscalar to vanish at the poles. The $AdS_2$ solutions with non-vanishing hyperscalar can naturally arise as the endpoint of holographic RG flows, triggered by relevant hyperscalar deformations of the $AdS_2$ solutions of the STU model.

We study the decay of general initial states out of a metastable potential well in quantum mechanics. We provide a closed-form expression for the probability current that tunnels through the barrier in terms of the resonant states into which the initial state can be decomposed. All ingredients in the equation are computed analytically to first subleading order in the semiclassical limit. Specializing to a coherently-oscillating initial state, we derive an approximation to the time-dependent decay rate and demonstrate its accuracy by comparing it to a numerical solution of the Schrödinger equation.

In this work, we investigate the magnetic properties of the quantum vacuum in the context of QED. We calculate the quantum relativistic correction of virtual particle-anti-particle pair creation to the field of a classical point-like idealized magnet. Using such correction, we find the induced currents stemming from the effect of the polarization of the vacuum, which behaves like a paramagnetic medium. We also calculate the correction to the electric dipole potential and show that the well-known symmetry between the classical fields of point electric and magnetic dipoles is broken at the quantum level. Lastly, to illustrate possible applications of our findings, we briefly discuss the effect of the corrections obtained here in the context of neutron-neutron scattering and the hyperfine splitting for hydrogen-like atoms.

The superconformal action can be gauge-fixed in a gauge where is leads to the Einstein frame supergravity defined by a Kahler potential $K(z, \bar z)$, or in a gauge where it leads to a Jordan frame supergravity defined by the frame function $\Omega(z, \bar z)$, in addition to $K(z, \bar z)$. We present new supergravity $\xi$-attractor models with non-minimal gravity coupling. They describe potentials with an exponential and a polynomial approach to the plateau. The previously known $\xi$-attractors in the large $\xi$ limit predicted the spectral index $n_{s} = 1-2/N$ and the tensor-to-scalar ratio $r\to {12\over N^2}$. The new $\xi$-attractors in the large $\xi$ limit predict $n_{s} \geq 1-2/N$ and $r\to 0$, which provides a better match to the recent observational data and makes these models a target for the future B-mode experiments with small $r$. New $\xi$-attractors have some features similar to those of Palatini attractors. However, we show that the Palatini gravity with nonminimal scalar coupling and an independent affine connection has no supergravity embedding.

A set of linear differential equations was recently put forward as higher-dimensional generalizations of the BPZ null-state equations in two-dimensional CFTs at large central charge. In this work, we derive these higher-dimensional equations from gravity, based on the AdS/CFT correspondence. A near-boundary expansion is employed to analyze a light scalar field equation in a black hole background. There is a decoupling mechanism in the bulk perturbative series at certain conformal dimensions, resulting in isolated lower-order equations. We find that the results agree with the previously proposed four-dimensional CFT equations, which capture the resummed contributions from minimal-twist multi-stress tensor operators. The holographic calculation also allows one to obtain additional CFT differential equations that extend beyond the near-lightcone regime.

Nonlinear hydrodynamic interactions can change the relaxation of fluctuations from exponential to power-law decay at late times. Schwinger-Keldysh effective field theory provides a standard framework for describing such fluctuation effects, where the nonlinear late-time behavior is encoded in loop corrections. Extracting this behavior requires identifying the singularities of loop integrals, whose structure becomes increasingly intricate beyond simple models. We apply Landau singularity analysis to two-point functions in effective field theories and determine the singularities induced by nonlinear interactions without performing the loop integrations explicitly. From these frequency-space singularities, we extract nonlinear relaxation modes that control the late-time behavior. When gapless modes are present, these modes produce power-law decay at late times. Our results give a systematic singularity-based description of nonlinear late-time relaxation in a broad class of macroscopic effective theories.

The model of a topological quantum computer is a promising one due to its natural resistance to noise and other errors. Operations in such a computer are implemented by braiding the trajectories of anyons. While it is easy to understand how to build one-qubit operations, two-qubit operations are more difficult. In arXiv:2412.20931 we suggested an approach to build such operations for a topological quantum computer based on SU(2) Chern-Simons theory with arbitrary level using cabling of knots. In this paper we discuss how this approach should be generalized to the SU(N) case, what the differences are, and which new problems arise.

We present the leading-color two-loop QCD corrections for Higgs-boson production in association with two jets through gluon fusion in the heavy-top effective theory. We provide analytic expressions for the finite remainders of the helicity amplitudes, written in terms of one-mass pentagon functions with spinor-helicity coefficients. These expressions are obtained by reconstructing the amplitudes from numerical finite-field samples computed within the numerical unitarity framework. The reconstruction is made possible by several advances in exploiting the analytic structure of the amplitudes, which both reduce the number of required samples and lead to compact representations. In particular, we introduce a new algorithm for multivariate partial fraction decomposition, based on a generic bivariate slice and a simplified treatment of ideal intersections. Using the resulting analytic expressions, we provide an efficient and stable implementation of their numerical evaluation, ready for phenomenological applications. Finally, we study the singularity structure of the remainders and confirm the existence of a threshold at non-degenerate physical momentum configurations, usually associated with massive virtual particle exchanges.

We explore a modification of QCD sum rules where, instead of Borel transforms of current correlators, one considers the correlators in coordinate space as functions of Euclidean time. Taking the nucleon channel as an example, we derive such Euclidean time sum rules and compare them with the traditional Borel sum rules. We show that a rough estimate of nucleon mass and residue is also possible working in coordinate space, but such sum rules are much more affected by the uncertainties in power corrections and continuum contribution than the Borel ones: the fiducial interval is practically absent.

In this paper, we investigate axion physics in 4D F-theory MSSM models. We derive the axion coupling term with QCD gauge fields and the axion potential from a top-down perspective, from both IIB superstring and the dual M-theory picture. For the explicit geometric model, we employ the "quadrillion" landscape of 4D F-theory models with the exact Standard Model chiral spectrum, and study simple base threefolds such as $\mathbb{P}^3$, $\mathbb{P}^1\times\mathbb{P}^2$, the generalized Hirzebruch threefold $\tilde{\mathbb{F}}_3$ and $\mathbb{P}^1\times\mathbb{P}^1\times\mathbb{P}^1$. We derive exclusion constraints on the Kähler moduli space of the base threefold from the CP violation angle, the Standard Model gauge coupling constants and the stretched Kähler cone condition. We find stringent constraints on the set of base divisors that should be rigid or rigidified by the inclusion of flux. For the allowed regions of the parameter space, we estimate the typical mass of detectable QCD axions to be around $10^{-9}$eV, and the axion decay constant to be around $f_a\sim 10^{15}$GeV.

We derive bounds on the lifetime of an evaporating black hole. The bound follows from energy conservation and purification, within the framework of `asymptotically semiclassical spacetimes'. We use the recently derived expression for the Bondi flux of Hawking radiation, together with the expression for the entanglement entropy of Hawking radiation at null infinity, to investigate the purification phase after the last semiclassical ray. We discuss the energy-cost of entanglement purification and we find a lower bound on the purification time of the black hole, which scales as $M_0^4/\hbar^{3/2}$, where $M_0$ is the initial black hole mass. Additionally, motivated by quantum gravity considerations, we include the additional assumption that a Planck mass black hole is metastable. With this assumption, we find that the the purification time is extended to be exponential in the square of the initial black hole mass, i.e. in its initial area. We find that the redshift exponent is negative in this purification phase, which indicates the existence of a white-hole remnant which releases information slowly. We comment on phenomenological implications for primordial black hole remnants.