A White Paper on keV sterile neutrino Dark Matter

The work of C. Giunti was partially supported by the research grant Theoretical Astroparticle Physics number 2012CPPYP7 under the program PRIN 2012 funded by the Ministero dellIstruzione, Universita e della Ricerca (MIUR). The authors of Section 2 would like to thank A. Vincent for discussion and comments. The work of A. Mirizzi is supported by the Italian Ministero dellIstruzione, Universita e Ricerca (MIUR) and Istituto Nazionale di Fisica Nucleare (INFN) through the Theoretical Astroparticle Physics projects. The work of A. Ibarra was supported in part by the DFG cluster of excellence Origin and Structure of the Universe and by the ERC Advanced Grant project FLAVOUR (267104). M. Viel is supported by the ERC StG cosmoIGM. The work of O. Dragoun was supported by the GACR (contract P203/12/1896) and the ASCR (contract IRP AV02 10480585). This work was supported in part by the Gottfried Wilhelm Leibniz Programme of the Deutsche Forschungsgemeinschaft (DFG) and the NSF grant PHY-1307372 at UCSD. M. Laine was supported in part by the Swiss National Science Foundation (SNF) under grant 200020-155935. A. Merle acknowledges partial support by the Micron Technology Foundation, Inc. V. Niro acknowledges support by Spanish MINECO through project FPA2012-31880, by Spanish MINECO (Centro de excelencia Severo Ochoa Program) under grant SEV-2012-0249 as well as the Spanish grants FPA2014-58183-P, Multidark CSD2009-00064 and SEV-2014-0398 (MINECO) and by the PROMETEOII/2014/084 grant from Generalitat Valenciana; the work of V. Niro was also supported by the Deutsche Forschungsgemeinschaft (DFG) through the Collaborative Research Centre SFB 676 Particles, Strings and the Early Universe (through an SFB fellowship). M. Drewes acknowledges support by the Gottfried Wilhelm Leibniz program of the Deutsche Forschungsgemeinschaft (DFG) and the DFG cluster of excellence Origin and Structure of the Universe. D. Robinson is supported by the NSF under grant No. PHY-1002399. Y. Tsai acknowledges support by the NSF under grant No. PHY-1315155 and the Maryland Center for Fundamental Physics. This research was partially supported by Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), (A. Gomes Dias, C.A. de S. Pires, and P.S. Rodrigues da Silva,), by Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), (A. Gomes Dias), and by the National Foundation for Science and Technology Development (NAFOSTED) of Vietnam under grant 103.03-2012.49 (N. Anh Ky and N. T. Hong Van). The work of J. Heeck is funded in part by IISN and by Belgian Science Policy (IAP VII/37). The work of N.E. Mavromatos is supported in part by the London Centre for Terauniverse Studies (LCTS), using funding from the European Research Council via the Advanced Investigator Grant 267352, and by the U.K. Science and Technology Facilities Council (STFC) under the research grants ST/J002798/1 and ST/L000326/1. The work of A. Pilaftsis is supported in part by the Lancaster-Manchester-Sheffield Consortium for Fundamental Physics, under STFC (UK) research grant: ST/J000418/1. L. Gastaldo would like to acknowledge the support by the DFG Research Unit FOR 2202 Neutrino Mass Determination by Electron Capture in 163Ho, ECH (funding under GA 2219/2-1). T. Lasserre would like to acknowledge the support of the Technische Universitat Munchen Institute for Advanced Study, funded by the German Excellence Initiative and the European Union Seventh Framework Programme under grant agreement No. 291763, as well as the European Union Marie Curie COFUND program. S.; r r Mertens gratefully acknowledges support of a Feodor Lynen fellowship by the Alexander von Humboldt Foundation and support by the Helmholtz Association. R. Shrock acknowledges support from the U.S. NSF grants NSF-PHY-13-16617 and NSF-PHY-16-1620628. The work of Y. F. Li, W. Liao, and Z. Xing is supported in part by the National Natural Science Foundation of China under Grant No. 11135009. Several authors acknowledge (partial) support by the European Union through the FP7 Marie Curie Actions ITN INVISIBLES (PITN-GA-2011-289442). Furthermore, his project has received funding from the European Unions Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreements No. 690575 (InvisiblesPlus RISE) and No. 674896 (Elusives ITN).