Simen Kvaal

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Bilde av Simen Kvaal
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Telefon +47 22855674
Rom V 234 B
Brukernavn

Min bakgrunn er fra fysikk og anvendt matematikk, og i 2012 begynte jeg å arbeide med kvantekjemi. Mine hovedinteresser er analyse og utvikling av beregningsmetoder for ikkerelativistiske systemer.

For tiden er jeg forsker på Trygve Helgakers ERC advanced grant ABACUS, der jeg studerer formelle aspekter av tetthetsfunksjonalteori. Spesielt studerer jeg strømtetthetsfunksjonalteori for molekyler i ytre magnetiske felter.

Sent i 2014 ble jeg tildelt et ERC starting grant. Prosjektet BIVAQUM dykker ned i selve fundamentet for kvantemekanikk via det såkalte bivariasjonelle prinsipp. Dette er en generalisering av det konvensjonelle variasjonelle prinsipp som er fundamentet for omtrent alle beregningsskjema for kvantemekanikk, og representerer en svært ukonvensjonell innfallsvinkel, samtidig som potensialet er stort. Det bivariasjonelle prinsipp åpner opp helt nye måter å utlede og analysere metoder. Spesielt innen coupled-cluster-teori (enkel- og multireferanse) kan man gjøre helt nye ting ved hjelp av det bivariasjonelle prinsipp.

BIVAQUM har en egen nettside, se www.bivaqum.no.

 

Emneord: kjemi, teoretisk kjemi, coupled cluster theory, density functional theory, manybody theory

Publikasjoner

  • Kvaal, Simen & Helgaker, Trygve (2015). Ground-state densities from the Rayleigh-Ritz variation principle and from density-functional theory. Journal of Chemical Physics.  ISSN 0021-9606.  143(18) . doi: 10.1063/1.4934797
  • Jarlebring, Elias; Kvaal, Simen & Michiels, Wim (2014). An inverse iteration method for eigenvalue problems with eigenvector nonlinearities. SIAM Journal on Scientific Computing.  ISSN 1064-8275.  36(4), s A1978- A2001 . doi: 10.1137/130910014
  • Kvaal, Simen; Ekström, Ulf Egil; Teale, Andrew Michael & Helgaker, Trygve (2014). Differentiable but exact formulation of density-functional theory. Journal of Chemical Physics.  ISSN 0021-9606.  140(18) . doi: 10.1063/1.4867005
  • Tellgren, Erik; Kvaal, Simen & Helgaker, Trygve (2014). Fermion N -representability for prescribed density and paramagnetic current density. Physical Review A. Atomic, Molecular, and Optical Physics.  ISSN 1050-2947.  89(1) . doi: 10.1103/PhysRevA.89.012515 Fulltekst i vitenarkiv.
  • Kvaal, Simen (2013). Variational formulations of the coupled-cluster method in quantum chemistry. Molecular Physics.  ISSN 0026-8976.  111(9-11), s 1100- 1108 . doi: 10.1080/00268976.2013.812254
  • Halvorsen, Tore Gunnar & Kvaal, Simen (2012). Manifestly gauge invariant discretizations of the Schrodinger equation. Physics Letters A.  ISSN 0375-9601.  376(12-13), s 1107- 1114 . doi: 10.1016/j.physleta.2012.02.028
  • Kvaal, Simen (2012). Ab initio quantum dynamics using coupled-cluster. Journal of Chemical Physics.  ISSN 0021-9606.  136(19) . doi: 10.1063/1.4718427
  • Tellgren, Erik; Kvaal, Simen; Sagvolden, Espen; Ekström, Ulf Egil; Teale, Andrew Michael & Helgaker, Trygve (2012). Choice of basic variables in current-density-functional theory. Physical Review A. Atomic, Molecular, and Optical Physics.  ISSN 1050-2947.  86(6) . doi: 10.1103/PhysRevA.86.062506 Fulltekst i vitenarkiv.
  • Jarlebring, Elias; Kvaal, Simen & Michiels, Wim (2011). Computing all Pairs (lambda, mu) Such That lambda is a Double Eigenvalue of A + mu B. SIAM Journal on Matrix Analysis and Applications.  ISSN 0895-4798.  32, s 902- 927 . doi: 10.1137/100783157 Fulltekst i vitenarkiv.
  • Kvaal, Simen (2011). Multiconfigurational time-dependent Hartree method to describe particle loss due to absorbing boundary conditions. Physical Review A. Atomic, Molecular, and Optical Physics.  ISSN 1050-2947.  84(2) . doi: 10.1103/PhysRevA.84.022512
  • Kvaal, Simen; Jarlebring, Elias & Michiels, Wim (2011). Computing singularities of perturbation series. Physical Review A. Atomic, Molecular, and Optical Physics.  ISSN 1050-2947.  83(3) . doi: 10.1103/PhysRevA.83.032505
  • Pedersen Lohne, Magnus; Hagen, Gaute; Hjorth-Jensen, Morten; Kvaal, Simen & Pederiva, Francesco (2011). Ab initio computation of the energies of circular quantum dots. Physical Review B. Condensed Matter and Materials Physics.  ISSN 1098-0121.  84 . doi: 10.1103/PhysRevB.84.115302 Vis sammendrag
  • Selstø, Sølve; Birkeland, Tore; Kvaal, Simen; Nepstad, Raymond & Førre, Morten (2011). A master equation approach to double ionization of helium. Journal of Physics B: Atomic, Molecular and Optical Physics.  ISSN 0953-4075.  44(21) . doi: 10.1088/0953-4075/44/21/215003
  • Hjorth-Jensen, Morten; Dean, David Jarvis; Hagen, G. & Kvaal, Simen (2010). Many-body interactions and nuclear structure. Journal of Physics G: Nuclear and Particle Physics.  ISSN 0954-3899.  37(6) . doi: 10.1088/0954-3899/37/6/064035
  • Selstø, Sølve & Kvaal, Simen (2010). Absorbing boundary conditions for dynamical many-body quantum systems. Journal of Physics B: Atomic, Molecular and Optical Physics.  ISSN 0953-4075.  43(6) . doi: 10.1088/0953-4075/43/6/065004 Fulltekst i vitenarkiv.
  • Kvaal, Simen (2009). Harmonic oscillator eigenfunction expansions, quantum dots, and effective interactions. Physical Review B. Condensed Matter and Materials Physics.  ISSN 1098-0121.  80(4) . doi: 10.1103/PhysRevB.80.045321
  • Kvaal, Knut; Kucheryavski, Sergei V; Halstensen, Maths; Kvaal, Simen; Flø, Andreas Svarstad; Minkkinen, Pentti & Esbensen, Kim H. (2008). eAMTexplorer: a software package for texture and signal characterization using Angle Measure Technique. Journal of Chemometrics.  ISSN 0886-9383.  22(11-12), s 717- 721 . doi: 10.1002/cem.1160 Vis sammendrag
  • Kvaal, Simen (2008). Geometry of effective Hamiltonians. Physical Review C. Nuclear Physics.  ISSN 0556-2813.  78(4) . doi: 10.1103/PhysRevC.78.044330
  • Kvaal, Simen; Hjorth-Jensen, Morten & Nilsen, Halvor Møll (2007). Effective interactions, large-scale diagonalization, and one-dimensional quantum dots. Physical Review B. Condensed Matter and Materials Physics.  ISSN 1098-0121.  76 . doi: 0.1103/PhysRevB.76.085421 Vis sammendrag

Se alle arbeider i Cristin

  • Kvaal, Simen & Laestadius, Andre (2016). The extended coupled-cluster method and its rigorous analysis.
  • Laestadius, Andre & Kvaal, Simen (2016). Analysis of the Extended Coupled-Cluster Method.
  • Tellgren, Erik; Teale, Andrew Michael; Ekström, Ulf Egil; Kvaal, Simen; Sagvolden, Espen & Helgaker, Trygve (2015). Current density functional theory for molecular systems in strong magnetic fields.
  • Helgaker, Trygve; Borgoo, Alex; Ekström, Ulf Egil; Furness, James; Hoffmann, Mark; Kvaal, Simen; Lange, Kai Kaarvann; Reimann, Sarah; Sagvolden, Espen; Stopkowicz, Stella; Tellgren, Erik & Teale, Andrew Michael (2014). Density-Functional Theory in Magnetic Fields.
  • Helgaker, Trygve; Kvaal, Simen; Ekström, Ulf Egil & Teale, Andrew Michael (2014). Differentiable but Exact Formulation of Density-Functional Theory.
  • Helgaker, Trygve; Kvaal, Simen; Ekström, Ulf Egil & Teale, Andy (2014). Differentiable but Exact Formulation of Density-Functional Theory.
  • Helgaker, Trygve; Kvaal, Simen; Teale, Andrew Michael & Ekström, Ulf Egil (2014). Differentiable but Exact Formulation of Density-Functional Theory.
  • Helgaker, Trygve; Kvaal, Simen; Teale, Andrew Michael; Ekström, Ulf Egil; Jørgensen, Poul & Olsen, Jeppe (2014). Differentiable but Exact Formulation of Density-Functional Theory.
  • Kvaal, Simen (2014). Bivariational approximations & the orbital-adaptive coupled-cluster method.
  • Ekström, Ulf Egil; Kvaal, Simen; Borgoo, Alex; Helgaker, Trygve; Sagvolden, Espen & Tellgren, Erik (2013). Moreau-Yosida regularization of DFT.
  • Kvaal, Simen (2013). Ab initio dynamics using the coupled cluster method.
  • Kvaal, Simen (2013, 24. mai). Abels Tårn. [Radio].  NRK P2.
  • Kvaal, Simen; Ekström, Ulf Egil; Tellgren, Erik; Borgoo, Alex; Helgaker, Trygve & Sagvolden, Espen (2013). Moreau-Yosida regularization of DFT.
  • Sagvolden, Espen; Tellgren, Erik; Kvaal, Simen; Ekström, Ulf Egil; Teale, Andrew Michael & Helgaker, Trygve (2013). Building blocks of Current Density Functional Theory.
  • Sagvolden, Espen; Tellgren, Erik; Kvaal, Simen; Ekström, Ulf Egil; Teale, Andrew Michael & Helgaker, Trygve (2013). Building blocks of Current Density Functional Theory.
  • Selstø, Sølve; Kvaal, Simen; Birkeland, Tore; Nepstad, Raymond & Førre, Morten (2012). Double ionization with absorbers. EurophysicsNews.  ISSN 0531-7479.  43(1), s 15- 16
  • Kvaal, Simen (2010). Adaptive time-dependent coupled cluster method for wave-packet propagation of many-fermion systems.
  • Kvaal, Simen (2010). Time-dependent Coupled Cluster for Many-Body Quantum Dynamics.
  • Kvaal, Simen (2010). Time-dependent coupled-cluster approach to many-body quantum dynamics.
  • Kvaal, Simen (2010). Variational Principles for Coupled-Cluster Methods.
  • Kvaal, Simen; Jarlebring, Elias & Michiels, Wim (2010). A numerical method for computing the radius of convergence of Rayleigh Schroedinger Perturbation theory without the need for the terms in the series.
  • Selstø, Sølve; Førre, Morten; Kvaal, Simen; Nepstad, Raymond & Birkeland, Tore (2010). Describing double photo-ionization of helium bymeans of absorbing boundaries.
  • Selstø, Sølve & Kvaal, Simen (2010). Absorbing boundaries for more than one particle.
  • Selstø, Sølve & Kvaal, Simen (2010). Absorbing boundary conditions for dynamical many-particles systems.
  • Selstø, Sølve; Kvaal, Simen; Nepstad, Raymond & Førre, Morten (2010). Non-sequential double ionization of helium: Extracting the cross section.
  • Halvorsen, Tore Gunnar & Kvaal, Simen (2009). Manifestly gauge invariant discretizations of the Schrödinger equation.
  • Hjorth-Jensen, Morten & Kvaal, Simen (2009). Effective interactions and convergence criteria for configuration interaction methods.
  • Jarlebring, Elias; Kvaal, Simen & Michiels, Wim (2009). Computing all pairs (lambda,mu) such that lambda is a double eigenvalue of A + mu B. Fulltekst i vitenarkiv. Vis sammendrag
  • Kvaal, Simen (2009). Analysis of many-body methods for quantum dots.
  • Kvaal, Simen (2009). Rigorous analysis of ab initio calculations for parabolic quantum dots. Fulltekst i vitenarkiv.
  • Kvaal, Simen (2009). Usynlig Verden.
  • Kvaal, Simen & Halvorsen, Tore Gunnar (2009). One gauge to rule them all -- Gauge-invariant grid discretizations.
  • Hjorth-Jensen, Morten & Kvaal, Simen (2007). Similarity Transformations, Flow Equations and Many-Body Perturbation Theory: Role of Many-Body Forces.

Se alle arbeider i Cristin

Publisert 9. feb. 2012 10:25 - Sist endret 20. sep. 2016 14:48