  In this contribution, it is our aim to show that the Chern-Simons terms of
modified gravity can be understood as generated by the addition of a
3-dimensional algebraic manifold to an initial 11-dimensional space-time
manifold; this builds up an 11+3-dimensional space-time. In this system,
firstly, some fields living in the bulk join the fields that live on the
11-dimensional manifold, so that the rank of the gauge fields exceeds the
dimension of the algebra; consequently, there emerges an anomaly. To solve this
problem, another 11-dimensional manifold is included in the 11 +3-dimensional
space-time, and it interacts with the initial manifold by exchanging
Chern-Simons fields. This mechanism is able to remove the anomaly. Chern-Simons
terms actually produce an extra manifold between the pair of 11-dimensional
manifolds of the 11+3-space-time. Summing up over the topology of both the
11-dimensional manifolds and the topology of the exchanged Chern-Simons
manifold in the bulk , we conclude that the total topology shrinks to one,
which is in agreement with the main idea of the Big Bang theory.
