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1. The PLATO Mission

Author

Rauer, Heike, Aerts, Conny, Cabrera, Juan, Deleuil, Magali, Erikson, Anders, Gizon, Laurent, Goupil, Mariejo, Heras, Ana, Lorenzo-Alvarez, Jose, Marliani, Filippo, Martin-Garcia, César, Mas-Hesse, J. Miguel, O'Rourke, Laurence, Osborn, Hugh, Pagano, Isabella, Piotto, Giampaolo, Pollacco, Don, Ragazzoni, Roberto, Ramsay, Gavin, Udry, Stéphane, Appourchaux, Thierry, Benz, Willy, Brandeker, Alexis, Güdel, Manuel, Janot-Pacheco, Eduardo, Kabath, Petr, Kjeldsen, Hans, Min, Michiel, Santos, Nuno, Smith, Alan, Suarez, Juan-Carlos, Werner, Stephanie C., Aboudan, Alessio, Abreu, Manuel, a, Lorena Acu, Adams, Moritz, Adibekyan, Vardan, Affer, Laura, Agneray, François, Agnor, Craig, Børsen-Koch, Victor Aguirre, Ahmed, Saad, Aigrain, Suzanne, Al-Bahlawan, Ashraf, Gil, M de los Angeles Alcacera, Alei, Eleonora, Alencar, Silvia, Alexander, Richard, Alfonso-Garzón, Julia, Alibert, Yann, Prieto, Carlos Allende, Almeida, Leonardo, Sobrino, Roi Alonso, Altavilla, Giuseppe, Althaus, Christian, Trujillo, Luis Alonso Alvarez, Amarsi, Anish, Eiff, Matthias Ammler-von, Amôres, Eduardo, Andrade, Laerte, Antoniadis-Karnavas, Alexandros, António, Carlos, del Moral, Beatriz Aparicio, Appolloni, Matteo, Arena, Claudio, Armstrong, David, Aliaga, Jose Aroca, Asplund, Martin, Audenaert, Jeroen, Auricchio, Natalia, Avelino, Pedro, Baeke, Ann, Baillié, Kevin, Balado, Ana, Balagueró, Pau Ballber, Balestra, Andrea, Ball, Warrick, Ballans, Herve, Ballot, Jerome, Barban, Caroline, Barbary, Gaële, Barbieri, Mauro, Forteza, Sebasti Barceló, Barker, Adrian, Barklem, Paul, Barnes, Sydney, Navascues, David Barrado, Barragan, Oscar, Baruteau, Clément, Basu, Sarbani, Baudin, Frederic, Baumeister, Philipp, Bayliss, Daniel, Bazot, Michael, Beck, Paul G., Bedding, Tim, Belkacem, Kevin, Bellinger, Earl, Benatti, Serena, Benomar, Othman, Bérard, Diane, Bergemann, Maria, Bergomi, Maria, Bernardo, Pierre, Biazzo, Katia, Bignamini, Andrea, Bigot, Lionel, Billot, Nicolas, Binet, Martin, Biondi, David, Biondi, Federico, Birch, Aaron C., Bitsch, Bertram, Ceballos, Paz Victoria Bluhm, Bódi, Attila, Bognár, Zsófia, Boisse, Isabelle, Bolmont, Emeline, Bonanno, Alfio, Bonavita, Mariangela, Bonfanti, Andrea, Bonfils, Xavier, Bonito, Rosaria, Bonomo, Aldo Stefano, Börner, Anko, Saikia, Sudeshna Boro, Martín, Elisa Borreguero, Borsa, Francesco, Borsato, Luca, Bossini, Diego, Bouchy, Francois, Boué, Gwenaël, Boufleur, Rodrigo, Boumier, Patrick, Bourrier, Vincent, Bowman, Dominic M., Bozzo, Enrico, Bradley, Louisa, Bray, John, Bressan, Alessandro, Breton, Sylvain, Brienza, Daniele, Brito, Ana, Brogi, Matteo, Brown, Beverly, Brown, David J. A., Brun, Allan Sacha, Bruno, Giovanni, Bruns, Michael, Buchhave, Lars A., Bugnet, Lisa, Buldgen, Gaël, Burgess, Patrick, Busatta, Andrea, Busso, Giorgia, Buzasi, Derek, Caballero, José A., Cabral, Alexandre, Gomez, Juan-Francisco Cabrero, Calderone, Flavia, Cameron, Robert, Cameron, Andrew, Campante, Tiago, Gestal, Néstor Campos, Martins, Bruno Leonardo Canto, Cara, Christophe, Carone, Ludmila, Carrasco, Josep Manel, Casagrande, Luca, Casewell, Sarah L., Cassisi, Santi, Castellani, Marco, Castro, Matthieu, Catala, Claude, Fernández, Irene Catalán, Catelan, Márcio, Cegla, Heather, Cerruti, Chiara, Cessa, Virginie, Chadid, Merieme, Chaplin, William, Charpinet, Stephane, Chiappini, Cristina, Chiarucci, Simone, Chiavassa, Andrea, Chinellato, Simonetta, Chirulli, Giovanni, Christensen-Dalsgaard, Jørgen, Church, Ross, Claret, Antonio, Clarke, Cathie, Claudi, Riccardo, Clermont, Lionel, Coelho, Hugo, Coelho, Joao, Cogato, Fabrizio, Colomé, Josep, Condamin, Mathieu, García, Fernando Conde, Conseil, Simon, Corbard, Thierry, Correia, Alexandre C. M., Corsaro, Enrico, Cosentino, Rosario, Costes, Jean, Cottinelli, Andrea, Covone, Giovanni, Creevey, Orlagh L., Crida, Aurelien, Csizmadia, Szilard, Cunha, Margarida, Curry, Patrick, da Costa, Jefferson, da Silva, Francys, Dalal, Shweta, Damasso, Mario, Damiani, Cilia, Damiani, Francesco, Chagas, Maria Liduina das, Davies, Melvyn, Davies, Guy, Davies, Ben, Davison, Gary, de Almeida, Leandro, de Angeli, Francesca, de Barros, Susana Cristina Cabral, Leão, Izan de Castro, de Freitas, Daniel Brito, de Freitas, Marcia Cristina, De Martino, Domitilla, de Medeiros, José Renan, de Paula, Luiz Alberto, Gómez, Álvaro de Pedraza, de Plaa, Jelle, De Ridder, Joris, Deal, Morgan, Decin, Leen, Deeg, Hans, Innocenti, Scilla Degl, Deheuvels, Sebastien, del Burgo, Carlos, Del Sordo, Fabio, Delgado-Mena, Elisa, Demangeon, Olivier, Denk, Tilmann, Derekas, Aliz, Desert, Jean-Michel, Desidera, Silvano, Dexet, Marc, Di Criscienzo, Marcella, Di Giorgio, Anna Maria, Di Mauro, Maria Pia, Rial, Federico Jose Diaz, Díaz-García, José-Javier, Dima, Marco, Dinuzzi, Giacomo, Dionatos, Odysseas, Distefano, Elisa, Nascimento Jr., Jose-Dias do, Domingo, Albert, D'Orazi, Valentina, Dorn, Caroline, Doyle, Lauren, Duarte, Elena, Ducellier, Florent, Dumaye, Luc, Dumusque, Xavier, Dupret, Marc-Antoine, Eggenberger, Patrick, Ehrenreich, David, Eigmüller, Philipp, Eising, Johannes, Emilio, Marcelo, Eriksson, Kjell, Ermocida, Marco, Giribaldi, Riano Isidoro Escate, Eschen, Yoshi, ez, Lucía Espinosa Yá, Estrela, In s, Evans, Dafydd Wyn, Fabbian, Damian, Fabrizio, Michele, Faria, João Pedro, Farina, Maria, Farinato, Jacopo, Feliz, Dax, Feltzing, Sofia, Fenouillet, Thomas, Fernández, Miguel, Ferrari, Lorenza, Ferraz-Mello, Sylvio, Fialho, Fabio, Fienga, Agnes, Figueira, Pedro, Fiori, Laura, Flaccomio, Ettore, Focardi, Mauro, Foley, Steve, Fontignie, Jean, Ford, Dominic, Fornazier, Karin, Forveille, Thierry, Fossati, Luca, Franca, Rodrigo de Marca, da Silva, Lucas Franco, Frasca, Antonio, Fridlund, Malcolm, Furlan, Marco, Gabler, Sarah-Maria, Gaido, Marco, Gallagher, Andrew, Sempere, Paloma I. Gallego, Galli, Emanuele, García, Rafael A., Hernández, Antonio García, Munoz, Antonio Garcia, García-Vázquez, Hugo, Haba, Rafael Garrido, Gaulme, Patrick, Gauthier, Nicolas, Gehan, Charlotte, Gent, Matthew, Georgieva, Iskra, Ghigo, Mauro, Giana, Edoardo, Gill, Samuel, Girardi, Leo, Winter, Silvia Giuliatti, Giusi, Giovanni, da Silva, João Gomes, Zazo, Luis Jorge Gómez, Gomez-Lopez, Juan Manuel, Hernández, Jonay Isai González, Murillo, Kevin Gonzalez, Melchor, Alejandro Gonzalo, Gorius, Nicolas, Gouel, Pierre-Vincent, Goulty, Duncan, Granata, Valentina, Grenfell, John Lee, bach, Denis Grie, Grolleau, Emmanuel, Grouffal, Salomé, Grziwa, Sascha, Guarcello, Mario Giuseppe, Gueguen, Lo c, Guenther, Eike Wolf, Guilhem, Terrasa, Guillerot, Lucas, Guillot, Tristan, Guiot, Pierre, Guterman, Pascal, Gutiérrez, Antonio, Gutiérrez-Canales, Fernando, Hagelberg, Janis, Haldemann, Jonas, Hall, Cassandra, Handberg, Rasmus, Harrison, Ian, Harrison, Diana L., Hasiba, Johann, Haswell, Carole A., Hatalova, Petra, Hatzes, Artie, Haywood, Raphaelle, Hébrard, Guillaume, Heckes, Frank, Heiter, Ulrike, Hekker, Saskia, Heller, René, Helling, Christiane, Helminiak, Krzysztof, Hemsley, Simon, Heng, Kevin, Herbst, Konstantin, Hermans, Aline, Hermes, JJ, Torres, Nadia Hidalgo, Hinkel, Natalie, Hobbs, David, Hodgkin, Simon, Hofmann, Karl, Hojjatpanah, Saeed, Houdek, Günter, Huber, Daniel, Huesler, Joseph, Hui-Bon-Hoa, Alain, Huygen, Rik, Huynh, Duc-Dat, Iro, Nicolas, Irwin, Jonathan, Irwin, Mike, Izidoro, André, Jacquinod, Sophie, Jannsen, Nicholas Emborg, Janson, Markus, Jeszenszky, Harald, Jiang, Chen, Mancebo, Antonio José Jimenez, Jofre, Paula, Johansen, Anders, Johnston, Cole, Jones, Geraint, Kallinger, Thomas, Kálmán, Szilárd, Kanitz, Thomas, Karjalainen, Marie, Karjalainen, Raine, Karoff, Christoffer, Kawaler, Steven, Kawata, Daisuke, Keereman, Arnoud, Keiderling, David, Kennedy, Tom, Kenworthy, Matthew, Kerschbaum, Franz, Kidger, Mark, Kiefer, Flavien, Kintziger, Christian, Kislyakova, Kristina, Kiss, László, Klagyivik, Peter, Klahr, Hubert, Klevas, Jonas, Kochukhov, Oleg, Köhler, Ulrich, Kolb, Ulrich, Koncz, Alexander, Korth, Judith, Kostogryz, Nadiia, Kovács, Gábor, Kovács, József, Kozhura, Oleg, Krivova, Natalie, Kucinskas, Arunas, Kuhlemann, Ilyas, Kupka, Friedrich, Laauwen, Wouter, Labiano, Alvaro, Lagarde, Nadege, Laget, Philippe, Laky, Gunter, Lam, Kristine Wai Fun, Lambrechts, Michiel, Lammer, Helmut, Lanza, Antonino Francesco, Lanzafame, Alessandro, Martiz, Mariel Lares, Laskar, Jacques, Latter, Henrik, Lavanant, Tony, Lawrenson, Alastair, Lazzoni, Cecilia, Lebre, Agnes, Lebreton, Yveline, Etangs, Alain Lecavelier des, Lee, Katherine, Leinhardt, Zoe, Leleu, Adrien, Lendl, Monika, Leto, Giuseppe, Levillain, Yves, Libert, Anne-Sophie, Lichtenberg, Tim, Ligi, Roxanne, Lignieres, Francois, Lillo-Box, Jorge, Linsky, Jeffrey, Liu, John Scige, Loidolt, Dominik, Longval, Yuying, Lopes, Ilídio, Lorenzani, Andrea, Ludwig, Hans-Guenter, Lund, Mikkel, Lundkvist, Mia Sloth, Luri, Xavier, Maceroni, Carla, Madden, Sean, Madhusudhan, Nikku, Maggio, Antonio, Magliano, Christian, Magrin, Demetrio, Mahy, Laurent, Maibaum, Olaf, Malac-Allain, LeeRoy, Malapert, Jean-Christophe, Malavolta, Luca, Maldonado, Jesus, Mamonova, Elena, Manchon, Louis, Manjón, Andres, Mann, Andrew, Mantovan, Giacomo, Marafatto, Luca, Marconi, Marcella, Mardling, Rosemary, Marigo, Paola, Marinoni, Silvia, Marques, rico, Marques, Joao Pedro, Marrese, Paola Maria, Marshall, Douglas, Perales, Silvia Martínez, Mary, David, Marzari, Francesco, Masana, Eduard, Mascher, Andrina, Mathis, Stéphane, Mathur, Savita, Vodopivec, Iris Martín, Figueiredo, Ana Carolina Mattiuci, Maxted, Pierre F. L., Mazeh, Tsevi, Mazevet, Stephane, Mazzei, Francesco, McCormac, James, McMillan, Paul, Menou, Lucas, Merle, Thibault, Meru, Farzana, Mesa, Dino, Messina, Sergio, Mészáros, Szabolcs, Meunier, Nadége, Meunier, Jean-Charles, Micela, Giuseppina, Michaelis, Harald, Michel, Eric, Michielsen, Mathias, Michtchenko, Tatiana, Miglio, Andrea, Miguel, Yamila, Milligan, David, Mirouh, Giovanni, Mitchell, Morgan, Moedas, Nuno, Molendini, Francesca, Molnár, László, Mombarg, Joey, Montalban, Josefina, Montalto, Marco, Monteiro, Mário J. P. F. G., Sánchez, Francisco Montoro, Morales, Juan Carlos, Morales-Calderon, Maria, Morbidelli, Alessandro, Mordasini, Christoph, Moreau, Chrystel, Morel, Thierry, Morello, Guiseppe, Morin, Julien, Mortier, Annelies, Mosser, Beno t, Mourard, Denis, Mousis, Olivier, Moutou, Claire, Mowlavi, Nami, Moya, Andrés, Muehlmann, Prisca, Muirhead, Philip, Munari, Matteo, Musella, Ilaria, Mustill, Alexander James, Nardetto, Nicolas, Nardiello, Domenico, Narita, Norio, Nascimbeni, Valerio, Nash, Anna, Neiner, Coralie, Nelson, Richard P., Nettelmann, Nadine, Nicolini, Gianalfredo, Nielsen, Martin, Niemi, Sami-Matias, Noack, Lena, Noels-Grotsch, Arlette, Noll, Anthony, Norazman, Azib, Norton, Andrew J., Nsamba, Benard, Ofir, Aviv, Ogilvie, Gordon, Olander, Terese, Olivetto, Christian, Olofsson, Göran, Ong, Joel, Ortolani, Sergio, Oshagh, Mahmoudreza, Ottacher, Harald, Ottensamer, Roland, Ouazzani, Rhita-Maria, Paardekooper, Sijme-Jan, Pace, Emanuele, Pajas, Miriam, Palacios, Ana, Palandri, Gaelle, Palle, Enric, Paproth, Carsten, Parro, Vanderlei, Parviainen, Hannu, Granado, Javier Pascual, Passegger, Vera Maria, Pastor-Morales, Carmen, Pätzold, Martin, Pedersen, May Gade, Hidalgo, David Pena, Pepe, Francesco, Pereira, Filipe, Persson, Carina M., Pertenais, Martin, Peter, Gisbert, Petit, Antoine C., Petit, Pascal, Pezzuto, Stefania, Pichierri, Gabriele, Pietrinferni, Adriano, Pinheiro, Fernando, Pinsonneault, Marc, Plachy, Emese, Plasson, Philippe, Plez, Bertrand, Poppenhaeger, Katja, Poretti, Ennio, Portaluri, Elisa, Portell, Jordi, de Mello, Gustavo Frederico Porto, Poyatos, Julien, Pozuelos, Francisco J., Moroni, Pier Giorgio Prada, Pricopi, Dumitru, Prisinzano, Loredana, Quade, Matthias, Quirrenbach, Andreas, Reina, Julio Arturo Rabanal, Soares, Maria Cristina Rabello, Raimondo, Gabriella, Rainer, Monica, Rodón, Jose Ramón, Ramón-Ballesta, Alejandro, Zapata, Gonzalo Ramos, Rätz, Stefanie, Rauterberg, Christoph, Redman, Bob, Redmer, Ronald, Reese, Daniel, Regibo, Sara, Reiners, Ansgar, Reinhold, Timo, Renie, Christian, Ribas, Ignasi, Ribeiro, Sergio, Ricciardi, Thiago Pereira, Rice, Ken, Richard, Olivier, Riello, Marco, Rieutord, Michel, Ripepi, Vincenzo, Rixon, Guy, Rockstein, Steve, Ortiz, José Ramón Rodón, Rodríguez, María Teresa Rodrigo, Amor, Alberto Rodríguez, Díaz, Luisa Fernanda Rodríguez, Garcia, Juan Pablo Rodriguez, Rodriguez-Gomez, Julio, Roehlly, Yannick, Roig, Fernando, Rojas-Ayala, Bárbara, Rolf, Tobias, Rørsted, Jakob Lysgaard, Rosado, Hugo, Rosotti, Giovanni, Roth, Olivier, Roth, Markus, Rousseau, Alex, Roxburgh, Ian, Roy, Fabrice, Royer, Pierre, Ruane, Kirk, Mastropasqua, Sergio Rufini, de Galarreta, Claudia Ruiz, Russi, Andrea, Saar, Steven, Saillenfest, Melaine, Salaris, Maurizio, Salmon, Sebastien, Saltas, Ippocratis, Samadi, Réza, Samadi, Aunia, Samra, Dominic, da Silva, Tiago Sanches, Carrasco, Miguel Andrés Sánchez, Santerne, Alexandre, Pé, Amaia Santiago, Santoli, Francesco, Santos, ngela R. G., Mesa, Rosario Sanz, Sarro, Luis Manuel, Scandariato, Gaetano, Schäfer, Martin, Schlafly, Edward, Schmider, François-Xavier, Schneider, Jean, Schou, Jesper, Schunker, Hannah, Schwarzkopf, Gabriel Jörg, Serenelli, Aldo, Seynaeve, Dries, Shan, Yutong, Shapiro, Alexander, Shipman, Russel, Sicilia, Daniela, sanmartin, Maria Angeles Sierra, Sigot, Axelle, Silliman, Kyle, Silvotti, Roberto, Simon, Attila E., Napoli, Ricardo Simoyama, Skarka, Marek, Smalley, Barry, Smiljanic, Rodolfo, Smit, Samuel, Smith, Alexis, Smith, Leigh, Snellen, Ignas, Sódor, Ádám, Sohl, Frank, Solanki, Sami K., Sortino, Francesca, Sousa, Sérgio, Southworth, John, Souto, Diogo, Sozzetti, Alessandro, Stamatellos, Dimitris, Stassun, Keivan, Steller, Manfred, Stello, Dennis, Stelzer, Beate, Stiebeler, Ulrike, Stokholm, Amalie, Storelvmo, Trude, Strassmeier, Klaus, Strøm, Paul Anthony, Strugarek, Antoine, Sulis, Sophia, vanda, Michal, Szabados, László, Szabó, Róbert, Szabó, Gyula M., Szuszkiewicz, Ewa, Talens, Geert Jan, Teti, Daniele, Theisen, Tom, Thévenin, Frédéric, Thoul, Anne, Tiphene, Didier, Titz-Weider, Ruth, Tkachenko, Andrew, Tomecki, Daniel, Tonfat, Jorge, Tosi, Nicola, Trampedach, Regner, Traven, Gregor, Triaud, Amaury, Trønnes, Reidar, Tsantaki, Maria, Tschentscher, Matthias, Turin, Arnaud, Tvaruzka, Adam, Ulmer, Bernd, Ulmer-Moll, Solène, Ulusoy, Ceren, Umbriaco, Gabriele, Valencia, Diana, Valentini, Marica, Valio, Adriana, Guijarro, Ángel Luis Valverde, Van Eylen, Vincent, Van Grootel, Valerie, van Kempen, Tim A., Van Reeth, Timothy, Van Zelst, Iris, Vandenbussche, Bart, Vasiliou, Konstantinos, Vasilyev, Valeriy, de Mascarenhas, David Vaz, Vazan, Allona, Nunez, Marina Vela, Velloso, Eduardo Nunes, Ventura, Rita, Ventura, Paolo, Venturini, Julia, Trallero, Isabel Vera, Veras, Dimitri, Verdugo, Eva, Verma, Kuldeep, Vibert, Didier, Martinez, Tobias Vicanek, Vida, Krisztián, Vigan, Arthur, Villacorta, Antonio, Villaver, Eva, Aparicio, Marcos Villaverde, Viotto, Valentina, Vorobyov, Eduard, Vorontsov, Sergey, Wagner, Frank W., Walloschek, Thomas, Walton, Nicholas, Walton, Dave, Wang, Haiyang, Waters, Rens, Watson, Christopher, Wedemeyer, Sven, Weeks, Angharad, Weingrill, Jörg, Weiss, Annita, Wendler, Belinda, West, Richard, Westerdorff, Karsten, Westphal, Pierre-Amaury, Wheatley, Peter, White, Tim, Whittaker, Amadou, Wickhusen, Kai, Wilson, Thomas, Windsor, James, Winter, Othon, Winther, Mark Lykke, Winton, Alistair, Witteck, Ulrike, Witzke, Veronika, Woitke, Peter, Wolter, David, Wuchterl, Günther, Wyatt, Mark, Yang, Dan, Yu, Jie, Sanchez, Ricardo Zanmar, Osorio, María Rosa Zapatero, Zechmeister, Mathias, Zhou, Yixiao, Ziemke, Claas, and Zwintz, Konstanze

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Solar and Stellar Astrophysics
Abstract

PLATO (PLAnetary Transits and Oscillations of stars) is ESA's M3 mission designed to detect and characterise extrasolar planets and perform asteroseismic monitoring of a large number of stars. PLATO will detect small planets (down to <2 R_(Earth)) around bright stars (<11 mag), including terrestrial planets in the habitable zone of solar-like stars. With the complement of radial velocity observations from the ground, planets will be characterised for their radius, mass, and age with high accuracy (5 %, 10 %, 10 % for an Earth-Sun combination respectively). PLATO will provide us with a large-scale catalogue of well-characterised small planets up to intermediate orbital periods, relevant for a meaningful comparison to planet formation theories and to better understand planet evolution. It will make possible comparative exoplanetology to place our Solar System planets in a broader context. In parallel, PLATO will study (host) stars using asteroseismology, allowing us to determine the stellar properties with high accuracy, substantially enhancing our knowledge of stellar structure and evolution. The payload instrument consists of 26 cameras with 12cm aperture each. For at least four years, the mission will perform high-precision photometric measurements. Here we review the science objectives, present PLATO's target samples and fields, provide an overview of expected core science performance as well as a description of the instrument and the mission profile at the beginning of the serial production of the flight cameras. PLATO is scheduled for a launch date end 2026. This overview therefore provides a summary of the mission to the community in preparation of the upcoming operational phases.

Published
2024

2. Local cone multipliers and Cauchy-Szego projections in bounded symmetric domains

Author

Yagüe, Fernando Ballesta and Garrigós, Gustavo

Subjects
Mathematics - Analysis of PDEs
Abstract

We show that the cone multiplier satisfies local $L^p$-$L^q$ bounds only in the trivial range $1\leq q\leq 2\leq p\leq\infty$. To do so, we suitably adapt to this setting the proof of Fefferman for the ball multiplier. As a consequence we answer negatively a question by B\'ekoll\'e and Bonami (Colloq. Math. 68, 1995, 81-100), regarding the continuity from $L^p\to L^q$ of the Cauchy-Szeg\"o projections associated with a class of bounded symmetric domains in $\mathbb{C}^n$ with rank $r\geq2$., Comment: Pages 19, Figures 3. Minor corrections. To appear in Jour London Math Soc

Published
2024

3. TESS Cycle 2 observations of roAp stars with 2-min cadence data

Author

Holdsworth, D. L., Cunha, M. S., Lares-Martiz, M., Kurtz, D. W., Antoci, V., Forteza, S. Barceló, De Cat, P., Derekas, A., Kayhan, C., Ozuyar, D., Skarka, M., Hey, D. R., Shi, F., Bowman, D. M., Kobzar, O., Gómez, A. Ayala, Bognár, Zs., Buzasi, D. L., Ebadi, M., Fox-Machado, L., Hernández, A. García, Ghasemi, H., Guzik, J. A., Handberg, R., Handler, G., Hasanzadeh, A., Jayaraman, R., Khalack, V., Kochukhov, O., Lovekin, C. C., Mikołajczyk, P., Mkrtichian, D., Murphy, S. J., Niemczura, E., Olafsson, B. G., Pascual-Granado, J., Paunzen, E., Posiłek, N., Safari, A. Ramón-Ballesta H., Samadi-Ghadim, A., Smalley, B., Sódor, Á., Stateva, I., Suárez, J. C., Szabó, R., Wu, T., Ziaali, E., Zong, W., and Seager, S.

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

We present the results of a systematic search of the Transiting Exoplanet Survey Satellite (TESS) 2-min cadence data for new rapidly oscillating Ap (roAp) stars observed during the Cycle 2 phase of its mission. We find seven new roAp stars previously unreported as such and present the analysis of a further 25 roAp stars that are already known. Three of the new stars show multiperiodic pulsations, while all new members are rotationally variable stars, leading to almost 70 per cent (22) of the roAp stars presented being $\alpha^2$ CVn-type variable stars. We show that targeted observations of known chemically peculiar stars are likely to overlook many new roAp stars, and demonstrate that multi-epoch observations are necessary to see pulsational behaviour changes. We find a lack of roAp stars close to the blue edge of the theoretical roAp instability strip, and reaffirm that mode instability is observed more frequently with precise, space-based observations. In addition to the Cycle 2 observations, we analyse TESS data for all known roAp stars. This amounts to 18 further roAp stars observed by TESS. Finally, we list six known roAp stars that TESS is yet to observe. We deduce that the incidence of roAp stars amongst the Ap star population is just 5.5 per cent, raising fundamental questions about the conditions required to excite pulsations in Ap stars. This work, coupled with our previous work on roAp stars in Cycle 1 observations, presents the most comprehensive, homogeneous study of the roAp stars in the TESS nominal mission, with a collection of 112 confirmed roAp stars in total., Comment: Accepted for publication in MNRAS. 32 Pages, 2 Tables, 77 Figures

Published
2023

4. The CARMENES search for exoplanets around M dwarfs. Guaranteed time observations Data Release 1 (2016-2020)

Author

Ribas, I., Reiners, A., Zechmeister, M., Caballero, J. A., Morales, J. C., Sabotta, S., Baroch, D., Amado, P. J., Quirrenbach, A., Abril, M., Aceituno, J., Anglada-Escudé, G., Azzaro, M., Barrado, D., Béjar, V. J. S., de Haro, D. Benítez, Bergond, G., Bluhm, P., Ortega, R. Calvo, Guillén, C. Cardona, Chaturvedi, P., Cifuentes, C., Colomé, J., Cont, D., Cortés-Contreras, M., Czesla, S., Díez-Alonso, E., Dreizler, S., Duque-Arribas, C., Espinoza, N., Fernández, M., Fuhrmeister, B., Galadí-Enríquez, D., García-López, A., González-Álvarez, E., Hernández, J. I. González, Guenther, E. W., de Guindos, E., Hatzes, A. P., Henning, Th., Herrero, E., Hintz, D., Huelmo, Á. L., Jeffers, S. V., Johnson, E. N., de Juan, E., Kaminski, A., Kemmer, J., Khaimova, J., Khalafinejad, S., Kossakowski, D., Kürster, M., Labarga, F., Lafarga, M., Lalitha, S., Lampón, M., Lillo-Box, J., Lodieu, N., González, M. J. López, López-Puertas, M., Luque, R., Magán, H., Mancini, L., Marfil, E., Martín, E. L., Martín-Ruiz, S., Molaverdikhani, K., Montes, D., Nagel, E., Nortmann, L., Nowak, G., Pallé, E., Passegger, V. M., Pavlov, A., Pedraz, S., Perdelwitz, V., Perger, M., Ramón-Ballesta, A., Reffert, S., Revilla, D., Rodríguez, E., Rodríguez-López, C., Sadegi, S., Carrasco, M. Á. Sánchez, Sánchez-López, A., Sanz-Forcada, J., Schäfer, S., Schlecker, M., Schmitt, J. H. M. M., Schöfer, P., Schweitzer, A., Seifert, W., Shan, Y., Skrzypinski, S. L., Solano, E., Stahl, O., Stangret, M., Stock, S., Stürmer, J., Tabernero, H. M., Tal-Or, L., Trifonov, T., Vanaverbeke, S., Yan, F., and Osorio, M. R. Zapatero

Subjects
Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Solar and Stellar Astrophysics
Abstract

The CARMENES instrument was conceived to deliver high-accuracy radial velocity (RV) measurements with long-term stability to search for temperate rocky planets around a sample of nearby cool stars. The broad wavelength coverage was designed to provide a range of stellar activity indicators to assess the nature of potential RV signals and to provide valuable spectral information to help characterise the stellar targets. The CARMENES Data Release 1 (DR1) makes public all observations obtained during the CARMENES guaranteed time observations, which ran from 2016 to 2020 and collected 19,633 spectra for a sample of 362 targets. The CARMENES survey target selection was aimed at minimising biases, and about 70% of all known M dwarfs within 10 pc and accessible from Calar Alto were included. The data were pipeline-processed, and high-level data products, including 18,642 precise RVs for 345 targets, were derived. Time series data of spectroscopic activity indicators were also obtained. We discuss the characteristics of the CARMENES data, the statistical properties of the stellar sample, and the spectroscopic measurements. We show examples of the use of CARMENES data and provide a contextual view of the exoplanet population revealed by the survey, including 33 new planets, 17 re-analysed planets, and 26 confirmed planets from transiting candidate follow-up. A subsample of 238 targets was used to derive updated planet occurrence rates, yielding an overall average of 1.44+/-0.20 planets with 1 M_Earth < M sin i < 1000 M_Earth and 1 d < P_orb < 1000 d per star, and indicating that nearly every M dwarf hosts at least one planet. CARMENES data have proven very useful for identifying and measuring planetary companions as well as for additional applications, such as the determination of stellar properties, the characterisation of stellar activity, and the study of exoplanet atmospheres., Comment: Published in A&A (https://www.aanda.org/10.1051/0004-6361/202244879), 25 pages, 12 figures, Tables 1 and 2 only available online

Published
2023
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5. Reactmine: a statistical search algorithm for inferring chemical reactions from time series data

Author

Martinelli, Julien, Grignard, Jeremy, Soliman, Sylvain, Ballesta, Annabelle, and Fages, François

Subjects
Quantitative Biology - Quantitative Methods, Statistics - Machine Learning
Abstract

Inferring chemical reaction networks (CRN) from concentration time series is a challenge encouragedby the growing availability of quantitative temporal data at the cellular level. This motivates thedesign of algorithms to infer the preponderant reactions between the molecular species observed ina given biochemical process, and build CRN structure and kinetics models. Existing ODE-basedinference methods such as SINDy resort to least square regression combined with sparsity-enforcingpenalization, such as Lasso. However, we observe that these methods fail to learn sparse modelswhen the input time series are only available in wild type conditions, i.e. without the possibility toplay with combinations of zeroes in the initial conditions. We present a CRN inference algorithmwhich enforces sparsity by inferring reactions in a sequential fashion within a search tree of boundeddepth, ranking the inferred reaction candidates according to the variance of their kinetics on theirsupporting transitions, and re-optimizing the kinetic parameters of the CRN candidates on the wholetrace in a final pass. We show that Reactmine succeeds both on simulation data by retrievinghidden CRNs where SINDy fails, and on two real datasets, one of fluorescence videomicroscopyof cell cycle and circadian clock markers, the other one of biomedical measurements of systemiccircadian biomarkers possibly acting on clock gene expression in peripheral organs, by inferringpreponderant regulations in agreement with previous model-based analyses. The code is available athttps://gitlab.inria.fr/julmarti/crninf/ together with introductory notebooks.

Published
2022

6. Study of rotational splittings in $\delta$~Scuti stars using pattern finding techniques

Author

Ramón-Ballesta, A., Hernández, A. García, Suárez, J. C., Rodón, J. R., Pascual-Granado, J., and Garrido, R.

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

Detecting and understanding rotation in stellar interiors is nowadays one of the unsolved problems in stellar physics. Asteroseismology has been able to provide insights on rotation for the Sun, solar-like stars, and compact objects like white dwarfs. However, this is still very difficult for intermediate-mass stars. These stars are moderate-to-rapid rotators. Rotation splits and shifts the oscillation modes, which makes the oscillation spectrum more complex and harder to interpret. Here we study the oscillation patterns of a sample of benchmark $\delta$~Sct stars belonging to eclipsing binary systems with the objective to find the frequency spacing related to the rotational splitting ($\delta r$). For this task, we combine three techniques: the Fourier transform, the autocorrelation function, and the histogram of frequency differences. The last two showed a similar behaviour. For most of the stars, it was necessary to determine the large separation ($\Delta\nu$) prior to spot $\delta r$. This is the first time we may clearly state that one of the periodicities present in the p~modes oscillation spectra of $\delta$~Sct stars corresponds to the rotational splitting. This is true independently of the stellar rotation rate. These promising results pave the way to find a robust methodology to determine rotational splittings from the oscillation spectra of $\delta$~Sct stars and, thus, understanding the rotational profile of intermediate-mass pulsating stars., Comment: Accepted for publication in Monthly Notices of the Royal Astronomical Society

Published
2021
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7. TESS Cycle 1 observations of roAp stars with 2-min cadence data

Author

Holdsworth, D. L., Cunha, M. S., Kurtz, D. W., Antoci, V., Hey, D. R., Bowman, D. M., Kobzar, O., Buzasi, D. L., Kochukhov, O., Niemczura, E., Ozuyar, D., Shi, F., Szabó, R., Samadi-Ghadim, A., Bognár, Zs., Fox-Machado, L., Khalack, V., Lares-Martiz, M., Lovekin, C. C., Mikołajczyk, P., Mkrtichian, D., Pascual-Granado, J., Paunzen, E., Richey-Yowell, T., Sódor, Á., Sikora, J., Yang, T. Z., Brunsden, E., David-Uraz, A., Derekas, A., Hernández, A. García, Guzik, J. A., Hatamkhani, N., Handberg, R., Lambert, T. S., Lampens, P., Murphy, S. J., Monier, R., Pollard, K. R., Quitral-Manosalva, P., Ramón-Ballesta, A., Smalley, B., Stateva, I., and Vanderspek, R.

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

We present the results of a systematic search for new rapidly oscillating Ap (roAp) stars using the 2-min cadence data collected by the Transiting Exoplanet Survey Satellite (TESS) during its Cycle 1 observations. We identify 12 new roAp stars. Amongst these stars we discover the roAp star with the longest pulsation period, another with the shortest rotation period, and six with multiperiodic variability. In addition to these new roAp stars, we present an analysis of 44 known roAp stars observed by TESS during Cycle 1, providing the first high-precision and homogeneous sample of a significant fraction of the known roAp stars. The TESS observations have shown that almost 60 per cent (33) of our sample of stars are multiperiodic, providing excellent cases to test models of roAp pulsations, and from which the most rewarding asteroseismic results can be gleaned. We report four cases of the occurrence of rotationally split frequency multiplets that imply different mode geometries for the same degree modes in the same star. This provides a conundrum in applying the oblique pulsator model to the roAp stars. Finally, we report the discovery of non-linear mode interactions in $\alpha$ Cir (TIC 402546736, HD 128898) around the harmonic of the principal mode -- this is only the second case of such a phenomenon., Comment: Accepted for publication in MNRAS. 38 Pages, 50 Figures, 1 Table, 2 Appendices

Published
2021
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8. A giant exoplanet orbiting a very low-mass star challenges planet formation models

Author

Morales, J. C., Mustill, A. J., Ribas, I., Davies, M. B., Reiners, A., Bauer, F. F., Kossakowski, D., Herrero, E., Rodríguez, E., López-González, M. J., Rodríguez-López, C., Béjar, V. J. S., González-Cuesta, L., Luque, R., Pallé, E., Perger, M., Baroch, D., Johansen, A., Klahr, H., Mordasini, C., Anglada-Escudé, G., Caballero, J. A., Cortés-Contreras, M., Dreizler, S., Lafarga, M., Nagel, E., Passegger, V. M., Reffert, S., Rosich, A., Schweitzer, A., Tal-Or, L., Trifonov, T., Zechmeister, M., Quirrenbach, A., Amado, P. J., Guenther, E. W., Hagen, H. -J., Henning, T., Jeffers, S. V., Kaminski, A., Kürster, M., Montes, D., Seifert, W., Abellán, F. J., Abril, M., Aceituno, J., Aceituno, F. J., Alonso-Floriano, F. J., Eiff, M. Ammler-von, Antona, R., Arroyo-Torres, B., Azzaro, M., Barrado, D., Becerril-Jarque, S., Benítez, D., Berdiñas, Z. M., Bergond, G., Brinkmöller, M., del Burgo, C., Burn, R., Calvo-Ortega, R., Cano, J., Cárdenas, M. C., Guillén, C. Cardona, Carro, J., Casal, E., Casanova, V., Casasayas-Barris, N., Chaturvedi, P., Cifuentes, C., Claret, A., Colomé, J., Czesla, S., Díez-Alonso, E., Dorda, R., Emsenhuber, A., Fernández, M., Fernández-Martín, A., Ferro, I. M., Fuhrmeister, B., Galadí-Enríquez, D., Cava, I. Gallardo, Vargas, M. L. García, Garcia-Piquer, A., Gesa, L., González-Álvarez, E., Hernández, J. I. González, González-Peinado, R., Guàrdia, J., Guijarro, A., de Guindos, E., Hatzes, A. P., Hauschildt, P. H., Hedrosa, R. P., Hermelo, I., Arabi, R. Hernández, Otero, F. Hernández, Hintz, D., Holgado, G., Huber, A., Huke, P., Johnson, E. N., de Juan, E., Kehr, M., Kemmer, J., Kim, M., Klüter, J., Klutsch, A., Labarga, F., Labiche, N., Lalitha, S., Lampón, M., Lara, L. M., Launhardt, R., Lázaro, F. J., Lizon, J. -L., Llamas, M., Lodieu, N., del Fresno, M. López, Salas, J. F. López, López-Santiago, J., Madinabeitia, H. Magán, Mall, U., Mancini, L., Mandel, H., Marfil, E., Molina, J. A. Marín, Martín, E. L., Martín-Fernández, P., Martín-Ruiz, S., Martínez-Rodríguez, H., Marvin, C. J., Mirabet, E., Moya, A., Naranjo, V., Nelson, R. P., Nortmann, L., Nowak, G., Ofir, A., Pascual, J., Pavlov, A., Pedraz, S., Medialdea, D. Pérez, Pérez-Calpena, A., Perryman, M. A. C., Rabaza, O., Ballesta, A. Ramón, Rebolo, R., Redondo, P., Rix, H. -W., Rodler, F., Trinidad, A. Rodríguez, Sabotta, S., Sadegi, S., Salz, M., Sánchez-Blanco, E., Carrasco, M. A. Sánchez, Sánchez-López, A., Sanz-Forcada, J., Sarkis, P., Sarmiento, L. F., Schäfer, S., Schlecker, M., Schmitt, J. H. M. M., Schöfer, P., Solano, E., Sota, A., Stahl, O., Stock, S., Stuber, T., Stürmer, J., Suárez, J. C., Tabernero, H. M., Tulloch, S. M., Veredas, G., Vico-Linares, J. I., Vilardell, F., Wagner, K., Winkler, J., Wolthoff, V., Yan, F., and Osorio, M. R. Zapatero

Subjects
Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Solar and Stellar Astrophysics
Abstract

Statistical analyses from exoplanet surveys around low-mass stars indicate that super-Earth and Neptune-mass planets are more frequent than gas giants around such stars, in agreement with core accretion theory of planet formation. Using precise radial velocities derived from visual and near-infrared spectra, we report the discovery of a giant planet with a minimum mass of 0.46 Jupiter masses in an eccentric 204-day orbit around the very low-mass star GJ 3512. Dynamical models show that the high eccentricity of the orbit is most likely explained from planet-planet interactions. The reported planetary system challenges current formation theories and puts stringent constraints on the accretion and migration rates of planet formation and evolution models, indicating that disc instability may be more efficient in forming planets than previously thought., Comment: Manuscript author version. 41 pages, 11 figures

Published
2019
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9. The CARMENES search for exoplanets around M dwarfs. Two temperate Earth-mass planet candidates around Teegarden's Star

Author

Zechmeister, M., Dreizler, S., Ribas, I., Reiners, A., Caballero, J. A., Bauer, F. F., Béjar, V. J. S., González-Cuesta, L., Herrero, E., Lalitha, S., López-González, M. J., Luque, R., Morales, J. C., Pallé, E., Rodríguez, E., López, C. Rodríguez, Tal-Or, L., Anglada-Escudé, G., Quirrenbach, A., Amado, P. J., Abril, M., Aceituno, F. J., Aceituno, J., Alonso-Floriano, F. J., Eiff, M. Ammler-von, Jiménez, R. Antona, Anwand-Heerwart, H., Arroyo-Torres, B., Azzaro, M., Baroch, D., Barrado, D., Becerril, S., Benítez, D., Berdiñas, Z. M., Bergond, G., Bluhm, P., Brinkmöller, M., del Burgo, C., Ortega, R. Calvo, Cano, J., Guillén, C. Cardona, Carro, J., Vázquez, M. C. Cárdenas, Casal, E., Casasayas-Barris, N., Casanova, V., Chaturvedi, P., Cifuentes, C., Claret, A., Colomé, J., Cortés-Contreras, M., Czesla, S., Díez-Alonso, E., Dorda, R., Fernández, M., Fernández-Martín, A., Ferro, I. M., Fuhrmeister, B., Fukui, A., Galadí-Enríquez, D., Cava, I. Gallardo, de la Fuente, J. Garcia, Garcia-Piquer, A., Vargas, M. L. García, Gesa, L., Rueda, J. Góngora, González-Álvarez, E., Hernández, J. I. González, González-Peinado, R., Grözinger, U., Guàrdia, J., Guijarro, A., de Guindos, E., Hatzes, A. P., Hauschildt, P. H., Hedrosa, R. P., Helmling, J., Henning, T., Hermelo, I., Arabi, R. Hernández, Castaño, L. Hernández, Otero, F. Hernández, Hintz, D., Huke, P., Huber, A., Jeffers, S. V., Johnson, E. N., de Juan, E., Kaminski, A., Kemmer, J., Kim, M., Klahr, H., Klein, R., Klüter, J., Klutsch, A., Kossakowski, D., Kürster, M., Labarga, F., Lafarga, M., Llamas, M., Lampón, M., Lara, L. M., Launhardt, R., Lázaro, F. J., Lodieu, N., del Fresno, M. López, López-Comazzi, A., López-Puertas, M., Salas, J. F. López, López-Santiago, J., Madinabeitia, H. Magán, Mall, U., Mancini, L., Mandel, H., Marfil, E., Molina, J. A. Marín, Fernández, D. Maroto, Martín, E. L., Martín-Fernández, P., Martín-Ruiz, S., Marvin, C. J., Mirabet, E., Montañés-Rodríguez, P., Montes, D., Moreno-Raya, M. E., Nagel, E., Naranjo, V., Narita, N., Nortmann, L., Nowak, G., Ofir, A., Oshagh, M., Panduro, J., Parviainen, H., Pascual, J., Passegger, V. M., Pavlov, A., Pedraz, S., Pérez-Calpena, A., Medialdea, D. Pérez, Perger, M., Perryman, M. A. C., Rabaza, O., Ballesta, A. Ramón, Rebolo, R., Redondo, P., Reffert, S., Reinhardt, S., Rhode, P., Rix, H. -W., Rodler, F., Trinidad, A. Rodríguez, Rosich, A., Sadegi, S., Sánchez-Blanco, E., Carrasco, M. A. Sánchez, Sánchez-López, A., Sanz-Forcada, J., Sarkis, P., Sarmiento, L. F., Schäfer, S., Schmitt, J. H. M. M., Schöfer, P., Schweitzer, A., Seifert, W., Shulyak, D., Solano, E., Sota, A., Stahl, O., Stock, S., Strachan, J. B. P., Stuber, T., Stürmer, J., Suárez, J. C., Tabernero, H. M., Pinto, M. Tala, Trifonov, T., Veredas, G., Linares, J. I. Vico, Vilardell, F., Wagner, K., Wolthoff, V., Xu, W., Yan, F., and Osorio, M. R. Zapatero

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

Context. Teegarden's Star is the brightest and one of the nearest ultra-cool dwarfs in the solar neighbourhood. For its late spectral type (M7.0V), the star shows relatively little activity and is a prime target for near-infrared radial velocity surveys such as CARMENES. Aims. As part of the CARMENES search for exoplanets around M dwarfs, we obtained more than 200 radial-velocity measurements of Teegarden's Star and analysed them for planetary signals. Methods. We find periodic variability in the radial velocities of Teegarden's Star. We also studied photometric measurements to rule out stellar brightness variations mimicking planetary signals. Results. We find evidence for two planet candidates, each with $1.1M_\oplus$ minimum mass, orbiting at periods of 4.91 and 11.4 d, respectively. No evidence for planetary transits could be found in archival and follow-up photometry. Small photometric variability is suggestive of slow rotation and old age. Conclusions. The two planets are among the lowest-mass planets discovered so far, and they are the first Earth-mass planets around an ultra-cool dwarf for which the masses have been determined using radial velocities., Comment: A&A 627, A49. 26 pages, 17 figures, 6 tables. Press release available at http://www.astro.physik.uni-goettingen.de/~zechmeister/teegarden/teegarden.html. v2: two authors and one reference added

Published
2019
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10. Fractional hopping-type motion in columnar mesophase of semi-flexible rod-like particles

Author

Naderi, Saber, Pouget, Emilie, Ballesta, Pierre, van der Schoot, Paul, Lettinga, M. Paul, and Grelet, Eric

Subjects
Condensed Matter - Soft Condensed Matter
Abstract

We report on single-particle dynamics of strongly interacting filamentous fd virus particles in the liquid-crystalline columnar state in aqueous solution. From fluorescence microscopy we find that rare, discrete events take place, in which individual particles engage in sudden, jump-like motion along the main rod axis. The jump length distribution is bimodal and centered at half and full particle lengths. Our Brownian dynamics simulations of hard semi-flexible particles mimic our experiments, and indicate that full-length jumps must be due to collective dynamics in which particles move in string-like fashion in and between neighboring columns, while half jumps arise as a result of particles moving into defects. We find that the finite domain structure of the columnar phase strongly influences the observed dynamics., Comment: 5 pages, 4 figures, accepted by Phys. Rev. Lett

Published
2013

11. Wall slip and flow of concentrated hard-sphere colloidal suspensions

Author

Ballesta, P., Petekidis, G., Isa, L., Poon, W. C. K., and Besseling, R.

Subjects
Condensed Matter - Soft Condensed Matter
Abstract

We present a comprehensive study of the slip and flow of concentrated colloidal suspensions using cone-plate rheometry and simultaneous confocal imaging. In the colloidal glass regime, for smooth, non-stick walls, the solid nature of the suspension causes a transition in the rheology from Herschel-Bulkley (HB) bulk flow behavior at large stress to a Bingham-like slip behavior at low stress, which is suppressed for sufficient colloid-wall attraction or colloid-scale wall roughness. Visualization shows how the slip-shear transition depends on gap size and the boundary conditions at both walls and that partial slip persist well above the yield stress. A phenomenological model, incorporating the Bingham slip law and HB bulk flow, fully accounts for the behavior. Microscopically, the Bingham law is related to a thin (sub-colloidal) lubrication layer at the wall, giving rise to a characteristic dependence of slip parameters on particle size and concentration. We relate this to the suspension's osmotic pressure and yield stress and also analyze the influence of van der Waals interaction. For the largest concentrations, we observe non-uniform flow around the yield stress, in line with recent work on bulk shear-banding of concentrated pastes. We also describe residual slip in concentrated liquid suspensions, where the vanishing yield stress causes coexistence of (weak) slip and bulk shear flow for all measured rates.

Published
2012
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12. Interplay between a hydrodynamic instability and a phase transition: the Faraday instability in dispersions of rodlike colloids

Author

Ballesta, Pierre, Lettinga, M. Paul, and Manneville, Sebastien

Subjects
Condensed Matter - Soft Condensed Matter, Physics - Fluid Dynamics
Abstract

Strong effects of the Faraday instability on suspensions of rodlike colloidal particles are reported through measurements of the critical acceleration and of the surface wave amplitude. We show that the transition to parametrically excited surface waves displays discontinuous and hysteretic features. This subcritical behaviour is attributed to the shear-thinning properties of our colloidal suspensions thanks to a phenomenological model based on rheological data under large amplitude oscillatory shear. Birefringence measurements provide direct evidence that Faraday waves induce local nematic ordering of the rodlike colloids. While local alignment simply follows the surface oscillations for dilute, isotropic suspensions, permanent nematic patches are generated by surface waves in samples close to the isotropic-to-nematic transition and above the transition large domains align in the flow direction. This strong coupling between the fluid microstructure and a hydrodynamic instability is confirmed by numerical computations based on the microstructural response of rodlike viruses in shear flow., Comment: 8 pages, 6 figures

Published
2011
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13. Shear banding and flow-concentration coupling in colloidal glasses

Author

Besseling, R., Isa, L., Ballesta, P., Petekidis, G., Cates, M. E., and Poon, W. C. K.

Subjects
Condensed Matter - Soft Condensed Matter, Condensed Matter - Materials Science
Abstract

We report experiments on hard sphere colloidal glasses that reveal a type of shear banding hitherto unobserved in soft glasses. We present a scenario that relates this to an instability arising from shear-concentration coupling, a mechanism previously thought unimportant in this class of materials. Below a characteristic shear rate $\dot\gamma_c$ we observe increasingly non-linear velocity profiles and strongly localized flows. We attribute this trend to very slight concentration gradients (likely to evade direct detection) arising in the unstable flow regime. A simple model accounts for both the observed increase of $\dot\gamma_c$ with concentration, and the fluctuations observed in the flow., Comment: 4 pages, 4 figures, accepted for publication in Phys. Rev. Lett

Published
2010
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14. Shear-thickening induced by Faraday waves in dilute wormlike micelles

Author

Ballesta, P. and Manneville, S.

Subjects
Condensed Matter - Soft Condensed Matter
Abstract

We investigate the effect of surface waves generated by the Faraday instability on a shear-thickening surfactant solution under vertical vibrations. We show that a prolonged oscillation of the surface above the instability onset leads to an increase of the fluid viscosity. This phenomenon is evidenced by comparing the time needed for the instability to develop in the fluid at rest and once the fluid has been shaken above onset: pre-shaking may delay the instability by two orders of magnitude. A simple model based on a time-dependent viscosity is proposed which accounts quantitatively for the experimental observations., Comment: 7 pages, 3 figures

Published
2009
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15. Superposition rheology of shear-banding wormlike micelles

Author

Ballesta, P., Lettinga, M. P., and Manneville, S.

Subjects
Condensed Matter - Soft Condensed Matter
Abstract

Wormlike micelle solutions are submitted to small-amplitude oscillatory shear superimposed to steady shear in the shear banding regime. By imposing a shear oscillation, the interface between high- and low-shear regions oscillates in time. A two-fluid semi-phenomenological model is proposed for superposition rheology in the shear banding regime, which allows us to extract a characteristic velocity for the interface dynamics from experiments involving only a standard rheometer. Estimates of the stress diffusion coefficient ${\cal D}$ can also be inferred from such superposition experiments. The validity of our model is confirmed by directly recording the interface displacement using ultrasonic velocimetry., Comment: 24 pages, 13 figures

Published
2009
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16. The Faraday instability in wormlike micelle solutions

Author

Ballesta, P. and Manneville, S.

Subjects
Physics - Fluid Dynamics
Abstract

The behaviour of semi-dilute wormlike micelle solutions under vertical vibrations is investigated using classical measurements of the Faraday instability threshold along with two new experiments based on particle imaging velocimetry and birefringence. We provide evidence for the presence of oscillations of the critical acceleration and wave number with the vibration frequency, which are linked to oscillations of the velocity and birefringence fields along the vertical direction. These observations are interpreted in terms of standing elastic waves across the fluid layer. Such an interpretation is confirmed numerically by using the model proposed by S. Kumar [Phys. Rev. E 65, 026305 (2002)] for a viscoelastic fluid to calculate the velocity and deformation fields. Finally, further birefringence experiments above the instability threshold show that the Faraday instability does not induce disentanglement and breakage of the micellar network., Comment: 27 pages, 13 figures

Published
2009
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17. Slip and flow of hard-sphere colloidal glasses

Author

Ballesta, P., Besseling, R., Isa, L., Petekidis, G., and Poon, W. C. K.

Subjects
Condensed Matter - Soft Condensed Matter
Abstract

We study the flow of concentrated hard-sphere colloidal suspensions along smooth, non-stick walls using cone-plate rheometry and simultaneous confocal microscopy. In the glass regime, the global flow shows a transition from Herschel-Bulkley behavior at large shear rate to a characteristic Bingham slip response at small rates, absent for ergodic colloidal fluids. Imaging reveals both the `solid' microstructure during full slip and the local nature of the `slip to shear' transition. Both the local and global flow are described by a phenomenological model, and the associated Bingham slip parameters exhibit characteristic scaling with size and concentration of the hard spheres., Comment: 4 pages, 4 figures. Accepted for publication in PRL

Published
2008
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18. Unexpected drop of dynamical heterogeneities in colloidal suspensions approaching the jamming transition

Author

Ballesta, Pierre, Duri, Agnes, and Cipelletti, Luca

Subjects
Condensed Matter - Soft Condensed Matter
Abstract

As the glass (in molecular fluids\cite{Donth}) or the jamming (in colloids and grains\cite{LiuNature1998}) transitions are approached, the dynamics slow down dramatically with no marked structural changes. Dynamical heterogeneity (DH) plays a crucial role: structural relaxation occurs through correlated rearrangements of particle ``blobs'' of size $\xi$\cite{WeeksScience2000,DauchotPRL2005,Glotzer,Ediger}. On approaching these transitions, $\xi$ grows in glass-formers\cite{Glotzer,Ediger}, colloids\cite{WeeksScience2000,BerthierScience2005}, and driven granular materials\cite{KeysNaturePhys2007} alike, strengthening the analogies between the glass and the jamming transitions. However, little is known yet on the behavior of DH very close to dynamical arrest. Here, we measure in colloids the maximum of a ``dynamical susceptibility'', $\chi^*$, whose growth is usually associated to that of $\xi$\cite{LacevicPRE}. $\chi^*$ initially increases with volume fraction $\phi$, as in\cite{KeysNaturePhys2007}, but strikingly drops dramatically very close to jamming. We show that this unexpected behavior results from the competition between the growth of $\xi$ and the reduced particle displacements associated with rearrangements in very dense suspensions, unveiling a richer-than-expected scenario., Comment: 1st version originally submitted to Nature Physics. See the Nature Physics website fro the final, published version

Published
2008
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19. Fluctations and noise in time-resolved light scattering experiments : measuring temporally heterogeneous dynamics

Author

Duri, Agnes, Ballesta, Pierre, Cipelletti, Luca, Bissig, Hugo, and Trappe, Veronique

Subjects
Condensed Matter - Soft Condensed Matter
Abstract

We use Time Resolved Correlation (TRC), a recently introduced light scattering method, to study the dynamics of a variety of jammed, or glassy, soft materials. The output of a TRC experiment is cI(t,tau), the time series of the degree of correlation between the speckle patterns generated by the light scattered at time t and t+tau. We characterize the fluctuations of cI by calculating their Probability Density Function, their variance as a function of the lag tau, and their time autocorrelation function. The comparison between these quantities for a Brownian sample and for jammed materials indicate unambiguously that the slow dynamics measured in soft glasses is temporally heterogeneous. The analogies with recent experimental, numerical and theoretical work on temporal heterogeneity in the glassy dynamics are briefly discussed., Comment: date de la fin de redaction : 06/09/2004

Published
2004
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20. Signature of elasticity in the Faraday instability

Author

Ballesta, Pierre and Manneville, Sebastien

Subjects
Condensed Matter - Soft Condensed Matter
Abstract

We investigate the onset of the Faraday instability in a vertically vibrated wormlike micelle solution. In this strongly viscoelastic fluid, the critical acceleration and wavenumber are shown to present oscillations as a function of driving frequency and fluid height. This effect, unseen neither in simple fluids nor in previous experiments on polymeric fluids, is interpreted in terms of standing elastic waves between the disturbed surface and the container bottom. It is shown that the model of S. Kumar [Phys. Rev. E, {\bf 65}, 026305 (2002)] for a viscoelastic fluid accounts qualitatively for our experimental observations. Explanations for quantitative discrepancies are proposed, such as the influence of the nonlinear rheological behaviour of this complex fluid., Comment: 4 pages, 4 figures

Published
2004
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