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The publication

On Superconformal Field Theories Associated to Very Attractive Quartics

explores explicit constructions of SCFTs associated to so-called very
attractive quartic K3 hypersurfaces in CP^{3}. In particular, I argue
that orbifold techniques allow to construct such SCFTs which do not only carry
the complex structure but also the normalized Kähler form induced by the
embedding of the quartic in CP^{3}.

I have generalized this result to yield a construction of SCFTs associated to a family of smooth quartic K3 surfaces in

A Family of SCFTs hosting all very attractive relatives of the (2)^{4} Gepner model

- JHEP
**0603**:102 (2006) - hep-th/0512223

The relevant family of quartics has four real parameters, and a three-parameter
subfamily contains as a dense subset the very attractive ones which were
considered in the previous work. This yields the first known family of SCFTs
which simultaneously allows an explicit description in terms of smooth
algebraic K3 surfaces, Landau-Ginzburg models, and orbifolds. It can be viewed
as a pure complex structure deformation of the Gepner model (2)^{4}.
Hence this family of SCFTs is tailor made to apply and test modern techniques
in SCFT, e.g. for constructing boundary states in SCFTs by means of matrix
factorization. Indeed, as an application of my results, Brunner, Gaberdiel, and
Keller have carried out first steps in this program, see
hep-th/0603196
and also Schmidt-Colinet's
hep-th/0701128.
Possible further applications of my work on SCFTs associated to quartic K3
surfaces are concerned with BPS algebras and the chiral de Rham complex.

At rational parameters, where the underlying K3 surfaces in our family of quartics in particular enjoy complex multiplication, the corresponding SCFTs are not necessarily rational. This contradicts one of the many beliefs on the relation between complex multiplication in geometry and rationality in CFT.

The second publication furthermore gives a relation between the Ricci-flat
Kähler-Einstein metric on the Fermat quartic in CP^{3} on the one hand
and an orbifold limit of such a metric on a closely related K3 surface on the
other. This discovery might allow a numerical investigation of the Ricci-flat
Kähler-Einstein metric on the Fermat quartic using the methods of hep-th/0506129. Moreover, one
can hope that numerical investigations of SCFTs on smooth quartics could be
carried out more generally, as an application of these methods.

One main mathematical ingredient to this work has been a construction by
Hiroshi Inose, *On certain Kummer surfaces, which can be realized as
nonsingular quartic surfaces in P ^{3}*, J. Fac. Sci. Uni. Tokyo

Some of the background from geometry which is relevant for this work is summarized in

K3 en route From Geometry to Conformal Field Theory

- Proceedings of the 2013 Summer School “Geometric, Algebraic and Topological Methods for Quantum Field Theory” in Villa de Leyva, Colombia, World Scientific (2017), pp 75-110
- arXiv:1503.08426 [math.DG]

Topics include the complex and Kähler geometry of Calabi-Yau manifolds and their classification in low dimensions. I furthermore discuss toroidal superconformal field theories and their Z2-orbifolds, yielding a discussion of K3 surfaces as the simplest class of Calabi-Yau manifolds where non-linear sigma model constructions bear mysteries to the very day. The elliptic genus in CFT and in geometry is presented as an instructional piece of evidence in favor of a deep connection between geometry and conformal field theory.