Constructing warm inflationary model in finite temperature BIon

TL;DR

This paper develops a warm inflation model based on a BIon configuration with a thermal wormhole, linking cosmological parameters to wormhole properties, and predicts a Big Rip singularity consistent with observational data.

Contribution

It introduces a novel warm inflationary model in a BIonic system with a thermal wormhole, connecting brane dynamics to cosmological evolution and singularity predictions.

Findings

Universe ends in Big Rip at ~29 Gyr (WMAP/Planck)

Model fits observational data with spectral index ~0.96

Wormhole accelerates universe destruction

Abstract

We study warm inflationary universe model on the BIon in thermal background. The BIon is a configuration in flat space of a D-brane and a parallel anti-D-brane connected by a wormhole with F-string charge. When the branes and antibranes are well separated and the brane's spike is far from the antibrane's spike, wormhole isn't formed however when two branes are close to each other, they can be connected by a wormhole. In this condition, there exists many channels for flowing energy from extra dimensions into our universe and inflation may naturally occur in a warm region. We present a model that allows all cosmological parameters like the scale factor $a$, the Hubble parameter $H$ and universe energy density depend on the shape function and temperature of wormhole in transverse dimension between two branes. In our model, the expansion of 4D universe is controlled by the thermal wormhole between branes and ends up in Big-Rip singularity. We show that at this singularity, universe would be destroyed and one black F-string formed. Finally, we test our model against WMAP, Planck and BICEP2 data and obtain the ripping time. According to experimental data, $N\simeq 50$ case leads to $n_{s}\simeq 0.96$, where \emph{N} and $n_{s}$ are the number e-folds and the spectral index respectively. This standard case may be found in $0.01 < R_{Tensor-scalar } < 0.3$, where $R_{Tensor-scalar }$ is the tensor-scalar ratio. At this point, the finite time that Big Rip singularity occurs is $t_{rip}=29(Gyr)$ for WMAP and Planck data and $t_{rip}=27.5(Gyr)$ for BICEP2 data. Comparing this time with the time of Big Rip in brane-antibrane, we find that the wormhole in BIonic system accelerates the destruction of the universe.