Kohji Tsumura

The Contact Frontier in Galactic Civilization Networks: Radial Structure and the Galactic Habitable Zone

The probability of interstellar contact depends not only on the abundance of technological civilizations but also on their spatial connectivity. Treating civilizations as nodes linked whenever their separation is smaller than the distance a signal travels within a communicative l...

Lifetime Distributions in Galactic Civilization Networks: A Hierarchy of Moments and Connectivity Thresholds

The Drake equation uses only the mean lifetime of a communicating civilization. Do contact and connectivity depend on the mean alone? Here the single lifetime and communication range of earlier work become a joint distribution at fixed mean. Abundance depends on the first moment...