Panagiotis Leivadaros

arXiv2026

Taxonomy of Instanton Corrections in Infinite Distance Limits

Using the BPS-protected higher derivative $R^4$-term as an exactly solvable example, we analyze which instanton corrections are generated by a one-loop Schwinger integral over the light towers of states that arise in infinite distance limits in moduli space. We find that the Schwinger integral fully captures precisely those instantons whose action lies parametrically in the window $(Λ_{\rm sp}/M_{\rm light})^{-1}\le {\rm S}_{\rm inst}\le Λ_{\rm sp}/M_{\rm light}$, that is, instantons whose action is bounded by the ratio of the gravity cutoff and the mass scale of the lightest tower. This proposal is supported by considering the entire moduli space of toroidal compactifications in eight dimensions, together with a number of limits in seven dimensions. In each case, integrating out the light towers via the Schwinger integral reproduces the complete contribution of the instantons within the above window. We further recast the proposal in terms of the taxonomy classification, allowing us to determine the emergent instantonic spectrum associated with any infinite distance limit.

hep-th↗

arXiv2026

Comments on the Emergence of 4D Topological Amplitudes in M-Theory

The M-theoretic Emergence Proposal claims that all of the terms in the low-energy action arise from quantum effects. After reviewing the current status of this proposal, we focus on four-dimensional compactifications with $N=2$ supersymmetry, where kinetic terms are encoded in topological string amplitudes, such as the prepotential $F_0$. Evidence for the emergence of such terms was provided recently, where in particular it was shown that the classical cubic term in $F_0$ can be obtained by integrating out the light towers of states in the M-theory limit, using a novel regularization of the infinite sum over Gopakumar/Vafa invariants. We address two issues that were left open. First, we show that the regularization can be equivalently performed in complex structure moduli space and in Kähler moduli space. Second, we extend the proposed regularization to the linear terms in the one-loop prepotential $F_1$.

hep-th↗