Primordial black holes in non-Gaussian regimes

Primordial black holes (PBHs) can form in the early Universe from the collapse of rare, large density fluctuations. They have never been observed, but this fact is enough to constrain the amplitude of fluctuations on very small scales which cannot be otherwise probed. Because PBHs form only in very rare large fluctuations, the number of PBHs formed is extremely sensitive to changes in the shape of the tail of the fluctuation distribution - which depends on the amount of non-Gaussianity present. We first study how local non-Gaussianity of arbitrary size up to fifth order affects the abundance and constraints from PBHs, finding that they depend strongly on even small amounts of non-Gaussianity and the upper bound on the allowed amplitude of the power spectrum can vary by several orders of magnitude. The sign of the non-linearity parameters (f_{NL}, g_{NL}, etc) are particularly important. We also study the abundance and constraints from PBHs in the curvaton scenario, in which case the complete non-linear probability distribution is known, and find that truncating to any given order (i.e. to order f_{NL} or g_{NL}, etc) does not give accurate results

Macroscopic Many-Qubit Interactions in Superconducting Flux Qubits

Superconducting flux qubits are considered to investigate macroscopic many-qubit interactions. Many-qubit states based on current states can be manipulated through the current-phase relation in each superconducting loop. For flux qubit systems comprised of $N$ qubit loops, a general expression of low energy Hamiltonian is presented in terms of low energy levels of qubits and macroscopic quantum tunnelings between the many-qubit states. Many-qubit interactions classified by {\em Ising type- or tunnel-}exchange interactions can be observable experimentally. Flux qubit systems can provide various artificial-spin systems to study many-body systems that cannot be found naturally.Comment: 5 pages, 1 figur

There\u27s A Million Heroes in Each Corner of the U.S.A

[Verse 1] Virginia gave us Washington, way back in Sev’nty six Kentucky gave us Lincoln when our boys were in a fix Ohio gave us Grant and Dixie gave us Lee They fought it out and patched it up and made our history If you asked Uncle Sammy who could take their place today He’d rub his chin and with a grin he’d answer in this way. [Chorus] There’s a million heroes in each corner of the U.S.A. In cities and farms They’ve taken up arms The East and West have sent their best the rest are coming from the land of cotton You can bank on ev’ry loyal Yank to fight till the end of the fray When danger threatens they all rally ‘round That’s why the flag has never touched the ground There’s a million heroes in each corner of the U.S.A. [Verse 2] Columbus found America the home of peace and rest And Betsy Ross she found a flag to stand each battle test Tho’ heroes of the past have laid away the gun Their spirits live within the hearts of ev’ry native son Our flag is just as clean today as when it first was made each stripe and star a battle scar and still I’m not afraid. [Chorus