arXiv subjects

C. Schwartz

Publications and source records attributed to C. Schwartz.

5 recordsLinked to original sources

arXiv2026

Abrupt crystallization from shock-compressed CaSiO3 glass

We have performed in situ time-resolved X-ray diffraction at ~100 GPa on laser-shocked CaSiO3 glass to investigate the glass-to-crystal transition. At this extreme pressure, we observe the ultrafast crystallization of the CaSiO3 perovskite structure from the compressed amorphous phase, with a typical nucleation time of 1.69 +/- 0.10 ns and a final grainsize of ~20 nm. The grain size temporal evolution suggest a diffusion controlled transformation. Moreover, the observed concomitant explosive grain growth together with the release wave arrival into shocked CaSiO3 also suggests a role of the release in the nucleation process.

cond-mat.mtrl-sci↗

arXiv1999

The Algebras of Large N Matrix Mechanics

Extending early work, we formulate the large N matrix mechanics of general bosonic, fermionic and supersymmetric matrix models, including Matrix theory: The Hamiltonian framework of large N matrix mechanics provides a natural setting in which to study the algebras of the large N limit, including (reduced) Lie algebras, (reduced) supersymmetry algebras and free algebras. We find in particular a broad array of new free algebras which we call symmetric Cuntz algebras, interacting symmetric Cuntz algebras, symmetric Bose/Fermi/Cuntz algebras and symmetric Cuntz superalgebras, and we discuss the role of these algebras in solving the large N theory. Most important, the interacting Cuntz algebras are associated to a set of new (hidden) local quantities which are generically conserved only at large N. A number of other new large N phenomena are also observed, including the intrinsic nonlocality of the (reduced) trace class operators of the theory and a closely related large N field identification phenomenon which is associated to another set (this time nonlocal) of new conserved quantities at large N.

hep-th↗

arXiv1999

Infinite Dimensional Free Algebra and the Forms of the Master Field

We find an infinite dimensional free algebra which lives at large N in any SU(N)-invariant action or Hamiltonian theory of bosonic matrices. The natural basis of this algebra is a free-algebraic generalization of Chebyshev polynomials and the dual basis is closely related to the planar connected parts. This leads to a number of free-algebraic forms of the master field including an algebraic derivation of the Gopakumar-Gross form. For action theories, these forms of the master field immediately give a number of new free-algebraic packagings of the planar Schwinger-Dyson equations.

hep-th↗

arXiv1998

Coexisting conical bipolar and equatorial outflows from a high-mass protostar

The BN/KL region in the Orion molecular cloud is an archetype in the study of the formation of stars much more massive than the Sun. This region contains luminous young stars and protostars, but it is difficult to study because of overlying dust and gas. Our basic expectations are shaped to some extent by the present theoretical picture of star formation, the cornerstone of which is that protostars acrete gas from rotating equatorial disks, and shed angular momentum by ejecting gas in bipolar outflows. The main source of the outflow in the BN/KL region may be an object known as radio source I, which is commonly believed to be surrounded by a rotating disk of molecular material. Here we report high-resolution observations of silicon monoxide (SiO) and water maser emission from the gas surrounding source I; we show that within 60 AU (about the size of the Solar System), the region is dominated by a conical bipolar outflow, rather than the expected disk. A slower outflow, close to the equatorial plane of the protostellar system, extends to radii of 1,000 AU.

astro-ph↗

arXiv1997

Asymptotic Search for Ground States of SU(2) Matrix Theory

We introduce a complete set of gauge-invariant variables and a generalized Born-Oppenheimer formulation to search for normalizable zero-energy asymptotic solutions of the Schrodinger equation of SU(2) matrix theory. The asymptotic method gives only ground state candidates, which must be further tested for global stability. Our results include a set of such ground state candidates, including one state which is a singlet under spin(9).

hep-th↗