just in order to be able to point to it, I created a stub for *vector representation*

I’ll be using the “Feynman slash notation” “$A\!\!\!/$” a little, for the Clifford algebra element associated with a given vector $A$ in the given inner product space.

I forget if there is some native code to get this notation. Is there? Presently I am using the hack

```
A\!\!\!/
```

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created a stub for *Dirac current*, so far mostly just a pointer to details in *A first idea of quantum field theory*; and cross-linked with *baryogenesis*, *chiral anomaly*, *conserved current* and *Noether’s thoerem*

The entry *Clifford algebra* used to state the classification and Bott periodicty over the complex numbers, but not over the real numbers. I have added in now the relevant statements, straight from Lawson-Michelson:

Just the bare statements so far.

]]>have noted down the basic properties of the irreducible representations of the Lorentzian spin group, at *spin representation – Properties*.

gave *geometric algebra* an Idea-section

I have started an entry *Majorana spinor* with discussion of how the physicist’s concept going by that name is a *real structure* on a complex spin representation.

Initially I had wanted to just follow the note by Figueroa-O’Farrill, but either I am missing something or else there is a gap in the argument there.

So in particular at the moment I have just one direction “Majorana structure is real structure”, not the converse.

(And why is it that the proposition number cross referencing is again broken?)

]]>added to *eta invariant* a lightning section *On manifolds with boundaries: as sections of the determinant line*, essentially just a glorified pointer to Freed 95 for the time being.

I have moved the table of real spinor reps that was sitting at *spin representation* into a entry-for-inclusion of its own

and then !included it back into the entry, and now also !included into at *supersymmetry – Classification – Super Poincaré symmetry*.

started a hyperlinked index for the book *Spin geometry*

wrote a bare minimum into *Atiyah-Bott-Shapiro isomorphism*.

I suppose with all the entries on Witten genus and related what was missing was an entry titled *Dirac-Ramond operator*. So I created one and filled in a bare minimum.

As we discussed in another thread but maybe it should be announced separately: I have started an entry *Dirac operator on smooth loop space* with some bare minimum.

brief entry for *Velo-Zwanziger problem*

started a topic cluster table of contents *higher spin geometry - contents* and included it as a “floating table of contents” into relevant entries

have created an entry for *Bott periodicity*

brief remark *charge conjugation matrix*, just because I needed to be able to point to it

I needed a table *exceptional spinors and division algebras – table*, and so I have created one and included it into the relevant entries

created spin^c structure and twisted spin^c structure

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