Love, Theoretically


 
 
 
 PRAISE FOR ALI HAZELWOOD
 “A literary breakthrough. . . . The Love Hypothesis is a self-assured debut, and we hypothesize it’s just the first bit of greatness we’ll see from an author who somehow has the audacity to be both an academic powerhouse and [a] divinely talented novelist.”
 —Entertainment Weekly
 “Contemporary romance’s unicorn: the elusive marriage of deeply brainy and delightfully escapist. . . . The Love Hypothesis has wild commercial appeal, but the quieter secret is that there is a specific audience, made up of all the Olives in the world, who have deeply, ardently waited for this exact book.”
 —New York Times bestselling author Christina Lauren
 “With her sophomore novel, Ali Hazelwood proves that she is the perfect writer to show that science is sexy as hell, and that love can ‘STEM’ from the most unlikely places. She’s my newest must-buy author.”
 —Jodi Picoult, #1 New York Times bestselling author of Wish You Were Here
 “Funny, sexy, and smart. Ali Hazelwood did a terrific job with The Love Hypothesis.”
 —New York Times bestselling author Mariana Zapata
 “Gloriously nerdy and sexy, with on-point commentary about women in STEM.”
 —New York Times bestselling author Helen Hoang on Love on the Brain
 “STEMinists, assemble. Your world is about to be rocked.”
 —New York Times bestselling author Elena Armas on Love on the Brain
 “This tackles one of my favorite tropes—Grumpy meets Sunshine—in a fun and utterly endearing way. . . . I loved the nods toward fandom and romance novels, and I couldn’t put it down. Highly recommended!”
 —New York Times bestselling author Jessica Clare on The Love Hypothesis
 “Pure slow-burning gold with lots of chemistry.”
 —PopSugar
 “A beautifully written romantic comedy with a heroine you will instantly fall in love with, The Love Hypothesis is destined to earn a place on your keeper shelf.”
 —Elizabeth Everett, author of A Lady’s Formula for Love
 “Smart, witty dialogue and a diverse cast of likable secondary characters. . . . A realistic, amusing novel that readers won’t be able to put down.”
 —Library Journal (starred review)
 “Hilarious and heartwarming, The Love Hypothesis is romantic comedy at its best. . . . A perfect amalgamation of sex and science, sure to appeal to readers of Christina Lauren or Abby Jimenez.”
 —Shelf Awareness
 “With whip-smart and endearing characters, snappy prose, and a quirky take on a favorite trope, Hazelwood convincingly navigates the fraught shoals of academia.”
 —Publishers Weekly
 
 
 TITLES BY ALI HAZELWOOD
 
 
 
 
 The Love Hypothesis
 Love on the Brain
 Love, Theoretically
 
 LOATHE TO LOVE YOU
 
 Under One Roof
 Stuck with You
 Below Zero
 
 
 
 
 
 
 
 
 
 
 
 BERKLEY ROMANCE
 Published by Berkley
 An imprint of Penguin Random House LLC
 penguinrandomhouse.com
 
 Copyright © 2023 by Ali Hazelwood
 Penguin Random House supports copyright. Copyright fuels creativity, encourages diverse voices, promotes free speech, and creates a vibrant culture. Thank you for buying an authorized edition of this book and for complying with copyright laws by not reproducing, scanning, or distributing any part of it in any form without permission. You are supporting writers and allowing Penguin Random House to continue to publish books for every reader.
 BERKLEY and the BERKLEY and B colophon are registered trademarks of Penguin Random House LLC.
 Library of Congress Cataloging-in-Publication Data
 Names: Hazelwood, Ali, author.
 Title: Love, theoretically / Ali Hazelwood.
 Description: New York: Berkley Romance, 2023.
 Identifiers: LCCN 2022046963 (print) | LCCN 2022046964 (ebook) | ISBN 9780593336861 (trade paperback) | ISBN 9780593336878 (ebook)
 Classification: LCC PS3608.A98845 L75 2023 (print) | LCC PS3608.A98845 (ebook) | DDC 813/.6—dc23
 LC record available at https://lccn.loc.gov/2022046963
 LC ebook record available at https://lccn.loc.gov/2022046964
 First Edition: June 2023
 Cover illustration by lilithsaur
 Cover design by Vikki Chu
 Book design by Daniel Brount, adapted for ebook by Molly Jeszke
 This is a work of fiction. Names, characters, places, and incidents either are the product of the author’s imagination or are used fictitiously, and any resemblance to actual persons, living or dead, business establishments, events, or locales is entirely coincidental.
 pid_prh_6.0_143790368_c0_r0
 
 
 
 To all my readers, from the AO3 days to where we are now. The Adam and Olive cameo is for you. 
 
 
 
 
 
 PROLOGUE
 In my life I have experienced regret, embarrassment, maybe even a touch of agony. But nothing, absolutely nothing prepared me for the ignominy of finding myself in a bathroom stall, pressed against the arrogant older brother of the guy I’ve been pretending to date for the past six months.
 It’s an award-winning, rock-bottoming low. Especially when coupled with the knowledge that Jack Smith is saving my ass. When he picks me up by the waist to maneuver me around the cramped 
 
 
 
 1
 WAVES AND PARTICLES
 Twenty-four hours earlier
 All throughout middle school, my Halloween costume was the duality of light.
 I made it with a marker, drawing a bunch of circles and zigzag lines all over one of Dad’s white undershirts I’d rescued from the trash can. In hindsight, the production value was so low, not even the physics teacher managed to guess what it was. I never minded, though. I’d walk around the hallways hearing Bill Nye’s voice in my head, his