Detectability of a phantom-like braneworld model with the integrated Sachs-Wolfe effect

We Study a braneworld model in which a phantom-like behavior occurs with only cold dark matter and a cosmological constant, due to a large distance modification of gravity. With the addition of curvature. the are not strict enough to rule out models in which gravity is modified significantly on geometrical tests large scales. We show that this degeneracy in the parameter space is broken by the structure formation tests. such as the integrated Sachs-Wolfe effect. which can probe general relativity on large scales.