nLab bosonic modality

Contents

Context

Modalities, Closure and Reflection

Super-Geometry

Contents

Idea

On super smooth infinity-groupoids there is a modal operator ()\stackrel{\rightsquigarrow}{(-)} which projects onto the bosonic components of the supergeometry. On formal dual superalgebras this is given by passing to the body. In terms of physical fields this is the projection onto boson fields, which are hence the modal types of \rightsquigarrow, and so it makes sense to speak of the bosonic modality.

This has a left adjoint \rightrightarrows (which on superalgebras passes to the even-graded sub-algebra) and hence together these form an adjoint modality which may be thought of as characterizing the supergeometry. See at super smooth infinity-groupoid – Cohesion. With \rightrightarrows being opposite to \rightsquigarrow thereby, it makes sense to call it the fermionic modality.

Notice that the fermionic currents in physics (e.g. the electron density current) are indeed fermionic bilinears, i.e. are indeed in the even subalgebras of the underlying superalgebra.

fermions bosons \array{ fermions & \rightrightarrows &\stackrel{}{\dashv}& \rightsquigarrow & bosons }

The modal objects for \rightsquigarrow are the bosonic objects.

The right adjoint of the bosonic modality is the rheonomy modality.

See also

cohesion

tangent cohesion

differential cohesion

graded differential cohesion

singular cohesion

id id fermionic bosonic bosonic Rh rheonomic reduced infinitesimal infinitesimal & étale cohesive ʃ discrete discrete continuous * \array{ && id &\dashv& id \\ && \vee && \vee \\ &\stackrel{fermionic}{}& \rightrightarrows &\dashv& \rightsquigarrow & \stackrel{bosonic}{} \\ && \bot && \bot \\ &\stackrel{bosonic}{} & \rightsquigarrow &\dashv& \mathrm{R}\!\!\mathrm{h} & \stackrel{rheonomic}{} \\ && \vee && \vee \\ &\stackrel{reduced}{} & \Re &\dashv& \Im & \stackrel{infinitesimal}{} \\ && \bot && \bot \\ &\stackrel{infinitesimal}{}& \Im &\dashv& \& & \stackrel{\text{étale}}{} \\ && \vee && \vee \\ &\stackrel{cohesive}{}& \esh &\dashv& \flat & \stackrel{discrete}{} \\ && \bot && \bot \\ &\stackrel{discrete}{}& \flat &\dashv& \sharp & \stackrel{continuous}{} \\ && \vee && \vee \\ && \emptyset &\dashv& \ast }

Last revised on July 23, 2022 at 14:45:51. See the history of this page for a list of all contributions to it.