In this, part III, of our series of deriving the Standard ΛCDM Model of cosmology from Type-IIB SUGRA by an identification of the inflaton with the Gukov-Vafa-Witten topologically twisted Kähler modulus, we recall that in part two, we derived the action of the and the
branes of our system. To complete the derivation, we need the
-term, and to obtain it, we need an embedding in M-theory. Let us derive the
action in a curved background given by our metric. The effective action is given by:
has a Kaloper-Sorbo reduction to:
with:
where we have integrated out the fluctuation-modes in the
directions. The
brane covariant 2-form is composed of two terms:
with the field strength of the vector field
living on the brane and
the pullback of the space-time NS-NS two-form field to the worldvolume of the
-brane, with a Chern-Simons part induced by the RR field. With:
the volume of a fixed , then integrating over
gives us:
with:
and with coupling constants:
with our four-form given by:
Thus the -Chern-Simons term becomes:
with:
Now since the invariant 5-form is self-dual in 10-D, there must be a 4-form field in all 10-dimensions. Hence, our action becomes:
with:
Adding coincident -branes forces us to generalize the connection
with corresponding Chan-Patton
gauge fields and a Yukawa quiver gauge-theory describing the system.
After embedding the -brane in the same metric and Ramond-Ramond system, we get the following
-action:
with:
Hence, the -modified total action is:
with:
Note that the hypermultiplet covariant derivative is still of the form:
hence, we can do the following gauge transformations:
consistent with:
Thus, our action now has the form:
Our string sectors and all our fields satisfy the required N = 1 chiral superfield-normalization condition and we have rigid N = 2 supersymmetry that gets naturally broken to N = 1 when coupled to gravity in D = 4. Now we need an embedding in M-theory in order to derive our -term. Take M-theory with
parallel
branes spread along the orbifold
, which preserves
SUSY in 4-D, with the wrapped 6-D background along
. Each
brane fills the 4-D non-compact spacetime and wraps the same holomorphic two-cycles
on the Calabi-Yau. The main terms of the 4-D
SYM theory are the volume modulus of the Calabi-Yau:

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
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![Rendered by QuickLaTeX.com \displaystyle \begin{array}{l}\mathcal{L}=-\frac{1}{2}\left\langle {{{D}^{\mu }}{{X}^{I}},{{D}_{\mu }}{{X}^{I}}} \right\rangle +\frac{i}{2}\left\langle {\bar{\Psi },{{\Gamma }^{\mu }}{{D}_{\mu }}\Psi } \right\rangle \\+\frac{i}{4}\left\langle {\bar{\Psi },{{\Gamma }_{{IJ}}}\left[ {{{X}^{I}},{{X}^{J}}\Psi } \right]} \right\rangle -{{V}_{X}}+{{\mathcal{L}}_{{CS}}}\end{array}](https://www.georgeshiber.com/wp-content/ql-cache/quicklatex.com-a9f831ec7eecee0c203b339eabdffd4f_l3.png)











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


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





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![Rendered by QuickLaTeX.com \displaystyle \begin{array}{l}{{\mathcal{L}}^{Q}}=-\frac{1}{2}\left[ {{{{\left( {{{\partial }_{\mu }}{{X}^{i}}} \right)}}^{2}}+{{{\left( {{{\partial }_{{\dot{\mu }}}}{{X}^{i}}} \right)}}^{2}}} \right]+\\\frac{i}{2}\left\langle {\bar{\Psi },\left( {{{\Gamma }^{\mu }}{{\partial }_{\mu }}+{{\Gamma }^{{\dot{\mu }}}}{{\partial }_{{\dot{\mu }}}}} \right)\Psi } \right\rangle -\\\frac{1}{4}{{F}_{{\mu \dot{\nu }\dot{\lambda }}}}^{2}-\frac{1}{{12}}{{F}_{{\dot{\mu }\dot{\nu }\dot{\lambda }}}}^{2}-\frac{1}{2}{{\epsilon }^{{\mu \nu \lambda }}}{{\epsilon }^{{\dot{\mu }\dot{\nu }\dot{\lambda }}}}{{\partial }_{\mu }}{{A}_{{\nu \dot{\mu }}}}{{\partial }_{{\dot{\nu }}}}{{A}_{{\lambda \dot{\lambda }}}}\end{array}](https://www.georgeshiber.com/wp-content/ql-cache/quicklatex.com-2e60523929b3692855ecff6f9f61ea1a_l3.png)






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



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

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


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
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











![Rendered by QuickLaTeX.com \displaystyle A_{\mu }^{B}=\frac{1}{{2M_{{{{p}_{l}}}}^{2}}}\text{i}\left[ {{{\varphi }_{i}}{{\partial }_{\mu }}{{\varphi }^{i}}-{{\varphi }^{i}}{{\partial }_{\mu }}{{\varphi }_{i}}} \right]+\frac{1}{{M_{{{{p}_{l}}}}^{2}}}{{W}_{\mu }}D](https://www.georgeshiber.com/wp-content/ql-cache/quicklatex.com-1791e6cf48114452a5a7fc441db88ca4_l3.png)
![Rendered by QuickLaTeX.com \displaystyle \frac{1}{{2M_{{{{p}_{l}}}}^{2}}}\text{i}\left[ {{{\varphi }_{i}}{{D}_{\mu }}{{\varphi }^{i}}-{{\varphi }^{i}}{{D}_{\mu }}{{\varphi }_{i}}} \right]+\frac{9}{{M_{{{{p}_{l}}}}^{2}}}{{W}_{\mu }}\xi](https://www.georgeshiber.com/wp-content/ql-cache/quicklatex.com-b82fa105333e486fcaf3406c2a323dcc_l3.png)





