Boris Kriger

Dear Colleague, I am writing to invite discussion and possible collaboration on a research program addressing one of the most persistent conceptual tensions in modern cosmology: the relationship between quantum vacuum energy and the cosmological constant. For several decades the standard ΛCDM model has effectively treated the quantum vacuum energy density as identical to the cosmological constant Λ, an assumption often traced to Zel’dovich’s proposal in 1967. While the model has been remarkably successful phenomenologically, this identification leads to the well-known discrepancy between theoretical estimates of vacuum energy in quantum field theory and the observed value of the cosmological constant — a mismatch often described as spanning roughly 120 orders of magnitude. The research program outlined in the attached preprints explores a different possibility: that the cosmological constant governing large-scale expansion and the gravitational effects of quantum vacuum energy may not be the same physical quantity. In this view, the vacuum may possess energy and structure — as indicated by phenomena such as the Higgs field, QCD condensates, and boundary-condition–dependent effects like the Casimir phenomenon — while its gravitational influence could manifest primarily in local or bound systems rather than as a uniform driver of cosmic expansion. The program therefore investigates whether it is possible to construct a consistent cosmological framework in which: • general relativity remains valid • quantum field theory in curved spacetime is respected • the Standard Model fields retain their known vacuum structure • no additional particles or forces are introduced The guiding question is straightforward: if vacuum energy exists physically, where and under what conditions should its gravitational effects appear? One hypothesis explored in the papers is that within gravitationally bound structures — galaxies, clusters, and similar systems where cosmic expansion is dynamically suppressed — the gravitational influence of vacuum energy might become locally relevant, while remaining effectively decoupled from the global expansion dynamics of the universe. The purpose of this message is not to advocate a finished theory, but rather to invite critical examination and collaboration. Because your work engages with related questions in cosmology, gravitation, or quantum fields, your perspective would be particularly valuable in evaluating whether this separation of phenomena could be developed into a consistent theoretical framework. Several preliminary preprints outlining the idea and its implications are available and can be shared upon request. If the question itself seems interesting — whether supportive, skeptical, or critical — I would be very glad to exchange thoughts or explore possible collaboration. With best regards, Boris Kriger Institute of Integrative and Interdisciplinary Research Toronto, Canada info@interdisciplinary-institute.org Preprints available on request.