Yashar Akrami @yasharakrami.bsky.social · 26/11/2025SCALE: Strings & Cosmology -- All Lengths Explored; May 11-15, 2026, Tenerife, Spain ➡️ Early-bird registration deadline: December 19, 2025 meetings.iac.es/scale2026 100
Yashar Akrami @yasharakrami.bsky.social · 08/04/2025Here is our recent paper, where we have shown that quintessence provides a very good fit to the DESI dark energy data, better than the cosmological constant, and that it prefers a curved universe: arxiv.org/abs/2504.04226arxiv.orgHas DESI detected exponential quintessence?The new Dark Energy Spectroscopic Instrument (DESI) DR2 results have strengthened the possibility that dark energy is dynamical, i.e., it has evolved over the history of the Universe. One simple, but ... 011
Yashar Akrami @yasharakrami.bsky.social · 02/04/2025To both cosmology and string theory communities: do not use simple phenomenological parametrizations (e.g., truncated Taylor expansions) of dark energy equation of state to conclude whether or not dark energy is dynamical -- see our recent paper: arxiv.org/abs/2503.22529arxiv.orgTo CPL, or not to CPL? What we have not learned about the dark energy equation of stateWe show that using a Taylor expansion for the dark energy equation-of-state parameter and limiting it to the zeroth and first-order terms, i.e., the so-called Chevallier-Polarski-Linder (CPL) parametr... 071
Yashar Akrami @yasharakrami.bsky.social · 16/03/2025Here is our new COMPACT collaboration paper, where we demonstrate that cosmic microwave background (CMB) polarization measurements from upcoming experiments can provide new avenues for detecting cosmic topology (i.e., the shape of the Universe): arxiv.org/abs/2503.08671arxiv.orgCosmic topology. Part IIIb. Eigenmodes and correlation matrices of spin-2 perturbations in orientable Euclidean manifoldsWe study the eigenmodes of the spin-2 Laplacian in orientable Euclidean manifolds and their implications for the tensor-induced part of the cosmic microwave background (CMB) temperature and polarizati... 020
Reposted by Yashar AkramiQuanta Magazine @quantamagazine.org · 27/01/2025Acoustic signatures in the cosmic microwave background could help researchers infer the shape of the universe. www.quantamagazine.org/cosmologists...quantamagazine.orgCosmologists Try a New Way to Measure the Shape of the Universe | Quanta MagazineIs the universe flat and infinite, or something more complex? We can’t say for sure, but a new search strategy is mapping out the subtle signals that would reveal if the universe had a shape. 26619
Reposted by Yashar AkramiQuanta Magazine @quantamagazine.org · 28/01/2025Is the universe a sphere, like the surface of Earth? Or maybe it’s shaped like a doughnut? Cosmologists believe that these possibilities could leave clues in the sky. New methods could help find them. buff.ly/3PTCOTo 14213
Reposted by Yashar AkramiInstituto de Física Teórica @iftuamcsic.bsky.social · 28/01/2025Is the universe infinite, or does it have a hidden shape waiting to be discovered? 🌌 Yashar Akrami (@yasharakrami.bsky.social) from #IFT is leading groundbreaking research on cosmic topology, featured in Quanta Magazine! Read more: www.quantamagazine.org/cosmologists...quantamagazine.orgCosmologists Try a New Way to Measure the Shape of the Universe | Quanta MagazineIs the universe flat and infinite, or something more complex? We can’t say for sure, but a new search strategy is mapping out the subtle signals that would reveal if the universe had a shape. 051
Yashar Akrami @yasharakrami.bsky.social · 27/01/2025Quanta Magazine just published a story about our searches for the topology of the Universe: 010
Yashar Akrami @yasharakrami.bsky.social · 11/12/2024Having Persian dinner with IFT's cosmology group. What a wonderful evening it was! @iftuamcsic.bsky.social 030