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This work uses the connection between hadronic stability and configurational entropy to explore hadronic structures written in terms of non-quadratic dilaton (κ z ) 2-α . These hadronic structures are described using the relation between the parameters κ and α with the constituent mass. We test Z c , Z b , and ψ as non- qq states defined as hybrid meson, hadroquarkonium, hadronic molecule, or diquark-antidiquark pair. We find that, holographically speaking, Z c and Z B are better described as a hybrid meson and ψ as hadrocharmonium.

We propose a general framework for the study of asymptotically flat spinning dyonic {\\it extremal} black holes (eBHs) in \\(D=4\\) Einstein-Maxwell-dilaton theory. Restricting to the stringy value \\(\\gamma=1\\) of the dilaton coupling constant, we report on the existence of a one parameter family of eBHs which are free of pathologies, provided their magnetic and electric charges are equal. An understanding of this condition is found from a study of the near horizon limit of the solutions, both perturbative closed form and numerical solutions being presented.

We study flows of \\(G_2\\)-structures guided by the principle of dimensional reduction: natural geometric flows in \\(G_2\\)-geometry reduce to natural flows in complex geometry. Our main examples are the \\(G_2\\)-Laplacian coflow, which lifts the K\"ahler--Ricci flow, and a 7-dimensional lift of the anomaly flow on complex threefolds. The \\(G_2\\)-lift of the anomaly flow deforms conformally coclosed \\(G_2\\)-structures. We compare the \\(G_2\\)-anomaly flow to the \\(G_2\\)-Laplacian coflow, and investigate short-time existence and fixed points.

The restricted quantum focusing conjecture (rQFC) plays a central role in an axiomatic formulation of semiclassical gravity. Since much hinges on its validity, it is imperative to subject the rQFC to rigorous tests in novel settings. Here we do so in two independent directions. First, we prove rQFC in a class of spacetime dimension \\(d=2\\) toy models, JT gravity coupled to a QFT. We also construct explicit counter-examples to the original and stronger Quantum Focusing Conjecture in a regime where matter quantum effects are comparable to the total dilaton value. Second, for \\(d>2\\), we derive from the rQFC a constraint stronger than the Quantum Null Energy Condition (QNEC). In a broad class of states, this bound forbids the QNEC from saturating faster than \\(O(\\mathcal{A})\\) as the transverse area \\(\\mathcal{A}\\) of a certain null deformation shrinks to zero. We speculate about a universal strengthened QNEC holding across all QFT states.

We investigate the scattering of two scalar glueballs in pure YM theory, using the well known dilaton potential. We perform the calculations considering a glueball mass of about m G ≈ 1.7 GeV, as predicted by lattice QCD. We begin with the tree-level theory, but the question about the presence of a bound state needs a deeper study to be answered. Thus we unitarize the theory through a self energy loop function consisting of a single subtraction at the single glueball resonance pole. We show that this choice is inconsistent as it leads to the emergence of a ghost-like state with negative norm. This problem is related with the sign of the coefficient in the first order term of the expansion of the reverse unitarized amplitude. We briefly discuss the solution which consists of an additional subtraction in the loop function, as presented in Eur.Phys.J.C 82 (2022) 5, 487.

A bstract We give an exposition of the SYK model with several new results. A non-local correction to the Schwarzian effective action is found. The same action is obtained by integrating out the bulk degrees of freedom in a certain variant of dilaton gravity. We also discuss general properties of out-of-time-order correlators.

Higher-derivative gravity theories offer insights into the behavior of extremely compact objects (ECOs). Focusing on Gauss-Bonnet (GB) and Einstein-dilaton-Gauss-Bonnet (EdGB) gravity, we derive the compactness scale in these models and demonstrate how higher-curvature corrections lead to deviations from the standard ECO compactness scale. The corrections are of order \\(\\alpha/r_0^2\\) in EGB gravity and \\(\\alpha^2/r_0^4\\) in EdGB gravity, where \\(\\alpha\\) is the coupling constant and \\(r_0\\) is the horizon radius corresponding to the mass of the ECO. Observational constraints suggest these effects could be significant in certain astrophysical systems, providing a new perspective on the nature of extremely compact objects in models of modified gravity.

We discuss the role of hyperelliptic fibrations in F-theory. For each even integer \\(n\\) we give a noncompact Calabi--Yau threefold \\(X\\) containing a hyperelliptically fibered surface \\(Y\\), such that \\(X\\) and \\(Y\\) are homotopy equivalent and \\(c_2(X) = n\\). We investigate two distinct cases depending on the position of the hyperelliptic fibration. First, we propose to extend F-theory considering hyperelliptic fibrations, giving an identification between the determinant of the period matrix and the axio-dilaton. Such an identification requires that the curve satisfies an appropriate criterium which we describe. Our explicit examples have split Jacobian, preserve the same number of degrees of freedom of usual F-theory, while allowing for the appearance of a greater variety of singularities. Second, when the hyperelliptic fibration is contained in the base of a Calabi--Yau fourfold, we show that tadpole cancellation conditions are satisfied for arbitrarily large values of \\(c_2(X)\\).

A bstract A Page curve for an evaporating black hole in asymptotically flat spacetime is computed by adapting the Quantum Ryu-Takayanagi (QRT) proposal to an analytically solvable semi-classical two-dimensional dilaton gravity theory. The Page time is found to be one third of the black hole lifetime, at leading order in semi-classical corrections. A Page curve is also obtained for a semi-classical eternal black hole, where energy loss due to Hawking evaporation is balanced by an incoming energy flux.

We study cosmological solutions of the IKKT model with \\(k=-1\\) FLWR geometry, taking into account one-loop corrections. A previously discussed covariant quantum spacetime is found to be stabilized through one-loop effects at early times, without adding a mass term to the model. At late times, this background is modified and approaches a solution of the classical model where \\(a(t) \\sim const\\), but the dilaton decreases in time. This suggests that a more complete treatment of the system is required in the late-time regime.