A bstract We introduce a new class of non-compact backgrounds Type IIB string theory preserving eight supercharges by combining S-folds and non-perturbative 7-branes wrapping orbifolds, study the four-dimensional superconformal field theories arising at low energy on D 3-branes probing them. draw precise correspondence between this setup torus compactification six-dimensional orbi-instanton with Stiefel-Whitney twist, use it to determine main features such strongly-coupled systems, like...

We propose a framework for treating F-theory directly, without resolving or deforming its singularities. This allows us to explore new sectors of gauge theories, including exotic bound states such as T-branes, in global context. use the mathematical known Eisenbud's matrix factorizations hypersurface display usefulness this technique by way examples, affine singularities both conifold and orbifold type, well class full-fledged compact elliptically fibered Calabi-Yau fourfolds.

We study the effective physics of F-theory at order $\alpha'^3$ in derivative expansion. show that ten-dimensional type IIB eight-derivative couplings involving graviton and axio-dilaton naturally descend from pure gravity twelve dimensions. Upon compactification on elliptically fibered Calabi-Yau fourfolds, non-trivial vacuum profile for leads to a new, genuinely N=1, correction four-dimensional action.

Bound states of 7-branes known as 'T-branes' have properties that defy usual geometric intuition. For instance, the gauge group n coincident branes may not be U(n). More surprisingly, matter show up at unexpected loci, such points. By analyzing T-branes perturbative type IIB string theory in tachyon condensation picture we gain following insights: a large class models, can diagonalized even though worldvolume Higgs cannot. In those cases, see structure these bound more manifestly, thereby...

We consider N=1 F-theory and Type IIB orientifold compactifications derive new \alpha' corrections to the four-dimensional effective action. They originate from higher derivative eleven-dimensional supergravity survive M-theory limit. find a correction Kahler moduli depending on non-trivial intersection curve of seven-branes. also analyze curvature correction.

We compactify four-dimensional $\mathcal{N}=1$ gauged supergravity theories on a circle including fluxes for shift-symmetric scalars. Four-dimensional Taub-NUT gravitational instantons universally correct the three-dimensional superpotential in absence of fluxes. In presence these instanton contributions are no longer gauge-invariant. Invariance can be restored by gauge-instantons top instantons. establish embedding this scenario into M-theory. Circle and gaugings arise from restricted class...

We perform a Kaluza–Klein reduction of eleven-dimensional supergravity on Calabi–Yau fourfold including terms quartic and cubic in the Riemann curvature determine induced corrections to three-dimensional two-derivative N=2 effective action. focus Einstein–Hilbert term kinetic for vectors. Dualizing vectors into scalars, we derive resulting Kähler potential complex coordinates. The classical expressions coordinates are non-trivially modified by containing third Chern form background fourfold,...

A bstract Extracting reliable low-energy information from string compactifications notoriously requires a detailed understanding of the UV sensitivity corresponding effective field theories. Despite past efforts in computing perturbative corrections to tree-level action, neither systematic approach nor unified framework has emerged yet. We make progress this direction, focusing on moduli dependence 4D scalar potential type IIB Calabi-Yau orientifold compactifications. proceed by employing...

D3 branes in the vicinity of an E6, E7, or E8 stack 7-branes flat space are known to host at low energy a famous class strongly-coupled N = 2 superconformal field theories featuring exceptional global symmetry. What if, instead, wrap orbifold? We give systematic characterization such case C2/Zn, and determine their main properties, like symmetries, spectra Coulomb-branch operators, patterns Higgs-branch flows. put forward set rules construct magnetic quivers, which directly generalize what...

A bstract We study the quantization of M-theory G-flux on elliptically fibered Calabi-Yau fourfolds with singularities giving rise to unitary and symplectic gauge groups. seek find its relation Freed-Witten worldvolume fluxes 7-branes in type IIB orientifold compactifications threefolds. By explicitly constructing appropriate four-cycles which calculate periods second Chern class fourfolds, we that there is a half-integral shift G -flux whenever corresponding dual 7-brane wrapped non-spin...

T-branes are exotic bound states of D-branes, characterized by mutually non-commuting vacuum expectation values for the worldvolume scalars. The M/F-theory geometry lifting D6/D7-brane configurations is blind to T-brane data. In this paper, we make data manifest, probing with an M2-brane. We find that effect a deform membrane superpotential monopole operators, which partially break three-dimensional flavor symmetry, and reduce super-symmetry from $$ \mathcal{N} = 4 2. Our main tool 3d mirror...

T-branes are supersymmetric configurations described by multiple Dp-branes with worldvolume flux and non-commuting vacuum expectation values for two of the scalars. When these much larger than string scale this description breaks down. We show that in regime correct is terms a single Dp-brane, whose curvature encodes T-brane data. present tale journey to reach picture, which takes us through T-dualities rugbyball-shaped brane no eye has gazed upon before.

A bstract We study the non-linear structure of Type IIB eight-derivative couplings involving metric and complexified three-form G 3 . show that, at level five-point string amplitudes, kinematics in maximally R-symmetry-violating sector is fully matched by standard superspace integrals superparticle amplitudes M-theory on a two-torus. The latter approach used to determine complete effective action this verify its invariance under SL(2, ℤ) duality. further comment general higher-point...

A bstract We work out the exact in g s and perturbatively α ′ result for vector multiplet moduli Kähler potential a specific $ \mathcal{N} = 2 compactification of F-theory. The well-known 3 correction is absent, but there rich structure corrections at all even orders . Moreover, each these independently displays an SL(2 , \mathbb{Z} ) invariant set string coupling constant. This generalizes earlier findings to case non-trivial elliptic fibration. Our results pave way analysis quantum more...

A bstract We use the F-theoretic engineering of four-dimensional rank-one superconformal field theories to provide a geometric understanding phenomenon supersymmetry enhancement along RG flow, recently observed by Maruyoshi and Song. In this context, superpotential deformations responsible for such flows are interpreted as T-brane backgrounds encoded in geometry elliptically-fibered fourfolds. formulate simple algebraic criterion select all supersymmetry-enhancing and, without any...

We analyse global aspects of 7-brane backgrounds with a non-commuting profile for their worldvolume scalars, also known as T-branes. In particular, we consider configurations no poles and globally well-defined over compact Kähler surface. find that such T-branes cannot be constructed on surfaces positive or vanishing Ricci curvature. For the existing T-branes, discuss stability move in moduli space at large volume provide examples splitting into non-mutually-supersymmetric constituents they...

A bstract The calculation of physical quantities in certain quantum field theories such as those the Argyres-Douglas type is notoriously hard, due to lack a Lagrangian description. Here we tackle this problem following two alternative approaches. On one hand, use localization on four-sphere compute two-correlators and OPE coefficients superconformal theories. other conformal bootstrap machinery put stringent bounds coefficients, only relying knowledge central charge dimension operators. We...

We find that the equations describing T-branes with constant worldvolume fields are identical to found by Banks, Seiberg and Shenker twenty years ago describe longitudinal five-branes in BFSS matrix model. Besides giving new ways construct T-brane solutions, this connection also helps elucidate physics of regime parameters where their larger than string scale. explicit solutions Banks-Seiberg-Shenker show corresponding admit an alternative description as Abelian branes at angles.

A bstract The computation of the partition function in certain quantum field theories, such as those Argyres-Douglas or Minahan-Nemeschansky type, is problematic due to lack a Lagrangian description. In this paper, we use holomorphic anomaly equation derive gravitational corrections prepotential theories at rank one by deforming them from conformal point. limit, find general formula for sum hypergeometric functions. We show explicit results round sphere and Nekrasov-Shatashvili phases Ω...

We study T-branes on compact Kaehler surfaces, in the presence of fields localised at curves. If such are treated as defects, their vevs induce delta-function sources for 7-brane background, possibly leading to profiles with poles. find that defect relaxes constraints globally well-defined T-brane configurations, avoiding obstruction building them surfaces positive curvature. Profiles poles can be understood, from a 4d viewpoint, non-trivial massive modes induced by and come own set...