Quantum systems coupled to environments via mean field interactions

Autor: Fantechi, Michele, Merkli, Marco

We show that when a quantum system is coupled to an environment in a mean field way, then its effective dynamics is governed by a unitary group with a time-dependent Hamiltonian. The time-dependent modification of the bare system Hamiltonian is given

Externí odkaz: http://arxiv.org/abs/2409.15850

On the stack of 0-dimensional coherent sheaves: motivic aspects

Autor: Fantechi, Barbara, Ricolfi, Andrea T.

Let $X$ be a variety. We study (decompositions of) the motivic class, in the Grothendieck ring of stacks, of the stack $\mathscr{C}oh^n(X)$ of $0$-dimensional coherent sheaves of length $n$ on $X$. To do so, we review the construction of the support

Externí odkaz: http://arxiv.org/abs/2403.07859

On the moduli space of simple sheaves on singular K3 surfaces

Autor: Fantechi, Barbara, Miró-Roig, Rosa M.

Mukai proved that the moduli space of simple sheaves on a smooth projective K3 surface is symplectic, and in \cite{FM2} we gave two constructions allowing one to construct new locally closed Lagrangian/isotropic subspaces of the moduli from old ones.

Externí odkaz: http://arxiv.org/abs/2403.00735

First observation and study of the $K^{\pm} \rightarrow \pi^{0} \pi^{0} \mu^{\pm} \nu$ decay

Autor: Collaboration, NA48/2, Batley, J. R., Kalmus, G., Lazzeroni, C., Munday, D. J., Slater, M. W., Wotton, S. A., Arcidiacono, R., Ceccucci, A., Bocquet, G., Cabibbo, N., Cundy, D., Falaleev, V., Gatignon, L., Fidecaro, M., Gonidec, A., Kubischta, W., Maier, A., Norton, A., Patel, M., Peters, A., Balev, S., Frabetti, P. L., Gersabeck, E., Goudzovski, E., Hristov, P., Kekelidze, V., Madigozhin, D., Molokanova, N., Polenkevich, I., Potrebenikov, Yu., Korotkova, A., Stoynev, S., Zinchenko, A., Kozhuharov, V., Litov, L., Monnier, E., Swallow, E., Winston, R., Rubin, P., Walker, A., Baldini, W., Ramusino, A. Cotta, Dalpiaz, P., Damiani, C., Fiorini, M., Gianoli, A., Martini, M., Petrucci, F., Savrié, M., Scarpa, M., Wahl, H., Bizzeti, A., Veltri, M., Calvetti, M., Celeghini, E., Iacopini, E., Lenti, M., Ruggiero, G., Behler, M., Eppard, K., Hita-Hochgesand, M., Kleinknecht, K., Marouelli, P., Masetti, L., Moosbrugger, U., Morales, C. Morales, Renk, B., Wache, M., Winhart, A., Wanke, R., Coward, D., Dabrowski, A., Martin, T. Fonseca, Shieh, M., Szleper, M., Velasco, M., Wood, M. D., Cenci, P., Pepe, M., Petrucci, M. C., Anzivino, G., Imbergamo, E., Nappi, A., Piccini, M., Raggi, M., Valdata-Nappi, M., Cerri, C., Fantechi, R., Collazuol, G., Di Lella, L., Lamanna, G., Mannelli, I., Michetti, A., Costantini, F., Doble, N., Fiorini, L., Giudici, S., Pierazzini, G., Sozzi, M., Venditti, S., Bloch-Devaux, B., Peyaud, B., Cheshkov, C., Chèze, J. B., De Beer, M., Derré, J., Marel, G., Mazzucato, E., Vallage, B., Holder, M., Ziolkowski, M., Biino, C., Cartiglia, N., Marchetto, F., Bifani, S., Clemencic, M., Lopez, S. Goy, Dibon, H., Jeitler, M., Markytan, M., Mikulec, I., Neuhofer, G., Widhalm, L.

Publikováno v: JHEP 03(2024)137

The NA48/2 experiment at CERN reports the first observation of the $K^{\pm} \rightarrow \pi^{0} \pi^{0} \mu^{\pm} \nu$ decay based on a sample of 2437 candidates with 15% background contamination collected in 2003--2004. The decay branching ratio in

Externí odkaz: http://arxiv.org/abs/2310.20295

Moduli of generalized syzygy bundles

Autor: Fantechi, Barbara, Miró-Roig, Rosa M.

Given a vector bundle $F$ on a variety $X$ and $W\subset H^0(F)$ such that the evaluation map $W\otimes \mathcal{O}_X\to F$ is surjective, its kernel $S_{F,W}$ is called generalized syzygy bundle. Under mild assumptions, we construct a moduli space $

Externí odkaz: http://arxiv.org/abs/2306.04317