Results 21 to 30 of about 41,884 (217)

Canonical forms for unitary congruence and *congruence [PDF]

, 2007
We use methods of the general theory of congruence and *congruence for complex matrices – regularization and cosquares – to determine a unitary congruence canonical form (respectively, a unitary *congruence canonical form) for complex matrices A such ...
R. Horn, V. Sergeichuk
semanticscholar   +1 more source

Integrable equations of the dispersionless Hirota type and hypersurfaces in the Lagrangian Grassmannian [PDF]

, 2007
We investigate integrable second order equations of the form F(u_{xx}, u_{xy}, u_{yy}, u_{xt}, u_{yt}, u_{tt})=0. Familiar examples include the Boyer-Finley equation, the potential form of the dispersionless Kadomtsev-Petviashvili equation, the ...
Ferapontov, E. V., Hadjikos, L., Khusnutdinova, K. R.   +2 more
core   +1 more source

A generalization of the injectivity condition for Projected Entangled Pair States

, 2018
We introduce a family of tensor network states that we term semi-injective Projected Entangled-Pair States (PEPS). They extend the class of injective PEPS and include other states, like the ground states of the AKLT and the CZX models in square lattices.
Cirac, J. Ignacio, Ge, Yimin, Molnar, Andras, Schuch, Norbert   +3 more
core   +1 more source

Time after time – circadian clocks through the lens of oscillator theory

FEBS Letters, EarlyView.
Oscillator theory bridges physics and circadian biology. Damped oscillators require external drivers, while limit cycles emerge from delayed feedback and nonlinearities. Coupling enables tissue‐level coherence, and entrainment aligns internal clocks with environmental cues.
Marta del Olmo, Carolin Ector, Hanspeter Herzel   +2 more
wiley   +1 more source

Survey on the Tukey theory of ultrafilters [PDF]

, 2014
This article surveys results regarding the Tukey theory of ultrafilters on countable base sets. The driving forces for this investigation are Isbell's Problem and the question of how closely related the Rudin-Keisler and Tukey reducibilities are.
Dobrinen, Natasha
core   +1 more source

Integrable (2+1)-dimensional systems of hydrodynamic type

, 2010
We describe the results that have so far been obtained in the classification problem for integrable (2+1)-dimensional systems of hydrodynamic type. The systems of Gibbons--Tsarev type are the most fundamental here.
A. C. Newell, A. V. Mikhailov, A. V. Mikhailov, A. V. Mikhailov, A. V. Odesskii, A. V. Odesskii, A. V. Odesskii, A. V. Odesskii, A. V. Odesskii, B. A. Dubrovin, B. A. Kupershmidt, D. J. Benney, E. V. Ferapontov, E. V. Ferapontov, E. V. Ferapontov, E. V. Ferapontov, E. V. Ferapontov, E. V. Ferapontov, E. V. Zakharov, I. M. Gel’fand, I. M. Krichever, I. M. Krichever, J. Gibbons, K. Löwner, K. Takasaki, L. A. Takhtadzhyan, L. Martínez Alonso, M. Mañas, M. V. Pavlov, M. V. Pavlov, M. V. Pavlov, M. V. Pavlov, M. V. Saveliev, S. P. Tsarëv, S. P. Tsarëv, S. V. Manakov, S. V. Manakov, T. Takebe, V. E. Zakharov, V. E. Zakharov, V. P. Spiridonov, V. Shramchenko, V. V. Sokolov   +42 more
core   +1 more source

On the determination of the dilaton-antisymmetric tensor couplings in supergravity theories [PDF]

, 1993
A new approach is provided to determine the dilaton--antisymmetric tensor coupling in a supergravity theory by considering the static supersymmetric field configuration around a super extended object, which is consistently formulated in a curved ...
Achucarro, Bergshoeff, Callan, Dabholkar, Duff, Duff, Duff, Duff, Duff, Duff, Hassan, Horowitz, J.X. Lu, Lu, Salam, Sen, Strathdee   +16 more
core   +3 more sources

Structural biology of ferritin nanocages

FEBS Letters, EarlyView.
Ferritin is a conserved iron‐storage protein that sequesters iron as a ferric mineral core within a nanocage, protecting cells from oxidative damage and maintaining iron homeostasis. This review discusses ferritin biology, structure, and function, and highlights recent cryo‐EM studies revealing mechanisms of ferritinophagy, cellular iron uptake, and ...
Eloise Mastrangelo, Flavio Di Pisa
wiley   +1 more source

Hamiltonian systems of hydrodynamic type in 2 + 1 dimensions

, 2007
We investigate multi-dimensional Hamiltonian systems associated with constant Poisson brackets of hydrodynamic type. A complete list of two- and three-component integrable Hamiltonians is obtained. All our examples possess dispersionless Lax pairs and an
A. Moro, B.A. Dubrovin, B.A. Dubrovin, C.P. Boyer, D.B. Fairlie, E. V. Ferapontov, E.V. Ferapontov, E.V. Ferapontov, E.V. Ferapontov, E.V. Ferapontov, I.M. Krichever, J. Gibbons, J. Gibbons, J. Haantjes, M. Blaszak, M. Blaszak, M. Burnat, M. Manas, M.V. Pavlov, O.I. Mokhov, S.K. Godunov, S.P. Tsarev, V. V. Sokolov, Z. Peradzyński   +23 more
core   +1 more source

Selfdual 4-Manifolds, Projective Surfaces, and the Dunajski-West Construction [PDF]

, 2014
I present a construction of real or complex selfdual conformal 4-manifolds (of signature (2,2) in the real case) from a natural gauge field equation on a real or complex projective surface, the gauge group being the group of diffeomorphisms of a real or ...
Calderbank, David M. J.
core   +5 more sources