Radiative stability of tiny cosmological constant from the swampland and quantized compactification

We address a quantization mechanism that can allow us to understand why the cosmological constant is not large under quantum corrections from studying circle compactification solution of Standard Model coupled Einstein gravity which subject constraint Swampland conjectures. A novel result in present work compared previous investigations literature radius compactified dimension and 4D $\Lambda_4$ must fact be quantized. The rule given by $\Lambda_4\propto n^2$ with $n=1,2,3,4,\ldots$, means values are arbitrary but only its specific allowed. In general, as well other effects would break this rule. Hence, it could prevent fluctuations generating zero-point energy contributions constant.