### Conveners

#### [DE] Dark energy

- Shinji Tsujikawa (Tokyo University of Science)

#### [DE] Dark energy

- Shinji Tsujikawa (Tokyo University of Science)

I will briefly introduce MTMG, and discuss its phenomenology for both the self-accelerating and normal branch.

We consider the finite interactions of the generalized Proca theory

including the sixth-order Lagrangian and derive the full linear perturbation

equations of motion on the flat Friedmann-Lema\^{i}tre-Robertson-Walker background

in the presence of a matter perfect fluid.

By construction, the propagating degrees of freedom (besides the matter perfect fluid)

are two transverse vector...

The time variation of the equation of state $w$ for quintessence scenario with a scalar field as dark energy is studied up to the third derivative ($d^3w/da^3$) with respect to the scale factor $a$, in order to predict the future observations and specify the scalar potential parameters. The third derivative of $w$ for general potential $V$ is derived and applied to several types of...

The latest cosmological observations by the Planck collaboration (and combined with others) are compatible with a phantom like behavior $(w<-1)$ for the dark energy equation of state that drives the current acceleration of the Universe. With this mindset we look into models where dark energy is described by a 3-form field minimally coupled to gravity. These models have the advantage, when...

On a warped five-dimensional Friedmann-Lema\^{\i}tre-Robertson-Walker(FLRW) spacetime, dark energy can be induced by a U(1) scalar-gauge field on the brane. We consider a zero effective cosmological constant, i.e., the Randall-Sundrum(RS) fine-tuning and no bulk matter fields. The standard model fields interact via the bulk Weyl tensor and cause brane fluctuations. Due to the warp factor,...

- Vacuum dark fluid presented by variable cosmological term

[I. Dymnikova, Phys. Lett. B 472 (2000) 33; I. Dymnikova, Class. Quant. Grav. 19 (2002) 725 (Honorable Mention-2001 of the Gravity Research Foundation); I. Dymnikova and E. Galaktionov, Phys. Lett. B 645 (2007) 358; I. Dymnikova, Int. J. Mod. Phys. A 31 (2016) 1641005]

- Regular Cosmologies with Vacuum Dark Energy

...

- One-horizon spacetimes.
- Holographic principle.
- Spacetime singled out by evaporation of the cosmological horizon.
- Lemaitre class model for relaxing cosmological constant.
- Cosmological evolution.
- Anisotropy.