  Braneworld scenarios appear in dynamical string tension theories, where
string tension is positive between two surfaces separated by a short distance
and at the two surfaces themselves the string tensions become infinite,
therefore producing an effective confinement of the strings and therefore of
all matter and gravity to the space between these to surfaces. The specific
model studied is in the context of the modified measure formulation the string
where tension appear as an additional dynamical degree of freedom and these
tensions are not universal, but rather each string generates its own tension,
which can have a different value for each string. We consider a new background
field that can couple to these strings, the tension scalar is capable then of
changing locally along the world sheet and then the value of the tension of the
string object changes accordingly along the world sheet. Sting tension appears
dynamically and each string tension has a characteristic constant of
integration that appears as a consequence of the dynamical tension generation .
When many types of strings probing the same region of space are considered this
tension scalar is constrained by the requirement of quantum conformal
invariance. For the case of two types of strings probing the same region of
space with different dynamically generated tensions (characterized by different
constants of integration) , there are two different metrics, associated to the
different strings, that have to satisfy vacuum Einsteins equations and the
consistency of these two Einsteins equations determine that the tension field
behaves. The two metrics are flat space in Minkowshi space and flat space after
a special conformal transformation, then the strings are confined inside a
light like Segment or alternatively as expanding Braneworlds where the strings
are confined between two expanding bubbles.
