# Cosmological constant in SUGRA models inspired by degenerate vacua

It is well known that global symmetries can protect a zero value for the cosmological constant in N=1 supergravity (SUGRA). The best motivated scenario of this type is no—scale supergravity where global symmetries guarantee not only vanishing of the vacuum energy density but also preserve local supersymmetry (SUSY) in all vacua. The breakdown of these symmetries that ensures the vanishing of the vacuum energy density near the physical vacuum leads to the natural realisation of the multiple point principle (MPP) assumption, i.e. results in the set of degenerate vacua with broken and unbroken local supersymmetry. We present the minimal SUGRA model where the MPP assumption is realised without any extra fine-tuning. The cosmological constant in the MPP inspired SUGRA models is naturally tiny $\rho_{\Lambda} << 10^{-100} M_{Pl}4$.

This talk is part of the HEP phenomenology joint Cavendish-DAMTP seminar series.

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